Miners Ridge Road-to-Trail Restoration Project at Prairie Creek State Park

The Miners Ridge Road-to-Trail Restoration Project was implemented to improve the recreational and wilderness quality of the Squashan Creek basin. The purpose of the project was to improve the aesthetic quality and reduce the future maintenance of the Miners Ridge Trail in Prairie Creek State Park. The project involved recontouring an old road that was no longer needed as a result of a trail reroute. In addition, a road was converted into a trail using heavy equipment. The secondary purpose was to reestablish natural flow paths and geomorphic features that were disrupted by road construction prior to park ownership. A total of 2,600 ft. of road was removed, and an additional 2,600 ft. of road was converted into a narrow hiking trail. A contractor operated a 20-mt excavator for 167.5 hours over a four-week period. An estimated 4,285 yd.³ of standard roadfill and 420 yd.³ of fill from 12 stream crossings were removed. A Sweco Trail Bulldozer operated by a park employee provided compaction. Minimal damage occurred to surrounding forest and aquatic resources.

This report describes the project implementation phase and provides a postconstruction review to critically analyze the project. This report does not explain technical details of road rehabilitation; rather, it serves as a supplement to existing reports. For background information on the Squashan Creek basin, see the Summary Report for Squashan Creek Watershed Restoration Project, prepared by California State Parks in December 1997. For information on road-to-trail conversions including descriptive graphics, see Last Chance Powerline Road Restoration Project, prepared by California State Parks in April 1998. Additional information on failures and successes of road-to-trail conversions can be found in the Annadel State Park trail project review memorandum prepared by the North Coast Redwoods District. General information on road recontouring can be found in Preacher Gulch Landform Rehabilitation, prepared by California State Parks in March 1999, or the Watershed Restoration Manual, prepared by Redwood National Park in 1992.

Trail Description

The Miners Ridge Trail connects Elk Prairie with Gold Bluffs Beach campground on the coast. The trail is one of the most popular day-use and overnight hiking routes in Prairie Creek State Park. The route provides options for a loop trail connecting Fern Canyon, coastal dunes, and ancient redwood forests surrounding the park visitor center. The trail follows Squashan Creek from the beach through coastal Sitka spruce rainforest, then climbs gently through old-growth redwood forests to the ridge top separating Prairie Creek and the Pacific Ocean.

Prior to the reconstruction project, the trail followed an industrial logging road up Squashan Creek that was used for timber extraction before park ownership. The industrial logging road was sidecast construction placed adjacent to Squashan Creek and had exposed numerous springs and seeps that caused constant saturation of the road/trail tread. Humboldt-style stream crossings involving logs placed in the channel instead of in culverts existed along the alignment, causing erosion problems during winter storms. The trail then followed an old corduroy road constructed during the earliest phase of logging that crossed Squashan Creek numerous times and traversed a wetland area. The trail then followed an old mine access road that climbed steeply up through old-growth forest, crossing numerous springs, seeps, and minor drainages.

A trail reroute was constructed in late 1998 to circumvent the old mine road and the corduroy-road segment. The trail reroute was 5,000 ft. long. The heavy-equipment phase of the project described below removed the abandoned road segments by creating a full recontour to the natural slope. The most important aspect of the project was to reconstruct the lower road segment into a narrow, reduced-maintenance, curvilinear, and geomorphically stable trail.

Survey Stations

On the road segments to be removed or reconstructed, distance stations made of 24-in. redwood stakes painted white were placed every 100 ft. Stakes were placed at the top of the existing road cut, and pink flagging was hung from nearby vegetation. The project was divided into an upper and lower segment to delineate the road removal from the road-to-trail conversion. The survey of the lower road-to-trail segment began at 00+00 adjacent to the uppermost Sand Filter Water Tank used for purification of the campground water supply and ended at 26+00 at the beginning of the trail reroute. The upper road-removal segment began at 00+00 adjacent to Squashan Creek where the road begins the climb up the eastern slope and ended at 26+00 at the upper end of the trail reroute.

Volume Survey

Volume surveys were conducted using standard methods described in the Redwood National Park Watershed Restoration Manual 1992. Road prism measurements were taken at obvious changes in the road profile and used to estimate perched volume per linear foot (see Figure 1).

Measurements included road bench-fill length, fill-slope length, and fill-slope angle. This information was not used for contract payments or sediment-reduction measurements. The volume estimate for this project is used for analysis of production rates for equipment-operator comparisons and will be used in the preparation of future contracts.

The volume survey for this project was difficult to implement because of the very thick vegetation cover on fill slopes and surrounding hillsides. Estimating the length of the fill slope was difficult because it was often unclear where the fill met the natural hillside. In the upper road segment, numerous old-growth redwood trees made fill estimates difficult. During the excavation of fill material, numerous large logs were removed, which were not visible during the initial survey that altered the actual soil volume moved. Also, in the road-to-trail conversion, some large trees growing on the fill slope were left standing to create a curvilinear trail, which altered the actual volume of material available for recontouring.

Prescriptions

Prior to the heavy-equipment work, Project Supervisor Don Beers, Geology Supervisor Patrick Vaughan, Engineering Geologist Brian Merrill, and Environmental Resources Intern Ethan Casaday hiked the project distance and developed prescriptions. Casaday noted a list of prescriptions during the field visit (see Table 1). Some misunderstanding resulted from differing viewpoints; however, a consensus was obtained for each station during the walk-through.

Contract Implementation

The contract work for this project was implemented between September 21 and October 14, 1999. From October 18 to October 21, 1999, state park personnel conducted additional heavy-equipment work. Because of environmental concerns regarding nesting of endangered wildlife, equipment work was scheduled to begin after September 15.

Operators and Equipment

The contractor for the implementation of the rehabilitation prescriptions was Steve Hemmingson Construction of Crescent City, CA. The equipment operator was Zeph Skeen of Hiochi, CA. Skeen has operated excavators, bulldozers, loaders, and other heavy equipment for over 20 years and has been involved in road-maintenance and road-removal contract work for state parks in the past.

The equipment used included an older Komatsu excavator, a new John Deere 200LC excavator, and a new Komatsu PC200LC excavator. The older Komatsu, owned by Hemmingson, was used only for the first two days, including the initial brush removal and construction of the ditch relief structure.

Equipment Move-In and Move-Out

The initial move-in up Miners Ridge Road began on September 21, 1999, and took 12 hours because of the necessity for brush removal. On September 23, the John Deere excavator was moved in and began work at upper station 25+00. This walk-in took three hours from Gold Bluffs Beach campground. During this time, the older Komatsu was moved down the road to upper station 00+00. The old Komatsu was then moved out on October 4, and a shorter transport vehicle was able to make the pickup at Gold Bluffs Beach. The new John Deere was then moved out on October 6, and the shorter transport vehicle was again able to make the pickup at Gold Bluffs Beach. On October 7, the new Komatsu was moved in to replace the John Deere and began work at lower station 22+20. The new Komatsu was then moved out on October 18, and the shorter transport vehicle was again able to make the pickup at Gold Bluffs Beach.

To protect the historic corduroy road, and because of wetland conditions in some areas, a 4×4 vehicle with a truck-bed fuel tank was not permitted to travel to the upper end of the project. For fuel supply, a 500-gal. off-highway diesel fuel tank was placed at the lower end of Miners Ridge Road. The tank was filled two times by a Renner fuel truck during the project. The tank was placed in a small depression lined with plastic for secondary-spill confinement. The tank was originally going to be placed farther up the road at lower station 00+00. However, an old bridge constructed of redwood logs with unknown weight limitations forced the tank location to be farther down the road. During the first week of the project, equipment work was 2 mi. from the fuel tank.

The excavator was filled daily by two park employees who transported fuel in 5-gal. cans on a motorized wheelbarrow from the tank to the work location. The park employees filled the excavator daily during the operator lunch break. The arrangement relieved the operator of all fueling responsibilities.

Upper Road Removal in Old-Growth Forest

The upper portion of this project involved the complete removal of 2,600 ft. of narrow forest road. The road removal took 83.5 hours over a 10-day period and included excavation of 1,840 yd.³ of roadfill and 140 yd.³ from four stream crossings (see Figure 2). The average production rate was 24 ft.³/hr. and 260 ft./day for the road removal.

A full recontour to the natural slope was obtained along the entire road-removal length. Organic material was separated from the fill and placed on the recontoured surface to protect against raindrop splash and sheet erosion. Because of the heavy load of organic material associated with the old-growth section of road, we were able to distribute a thick layer of logs, brush, and rotten material over most of the disturbed surface. Logs and large pieces of organic material were placed parallel to the slope and were tamped down to provide contact with the soil surface. In some places, the organic material placed on the final surface has 100% coverage and may be up to 3 ft. thick. At station 26+00, numerous logs were piled up to completely block the view of the road recontour from hikers traveling down the new trail reroute.

Stream crossings were excavated to recontour the natural channel shape, and an attempt was made to locate natural channel features. Additional logs were placed against the upper banks of stream crossings to prevent soil detachment from concentrated flow. The excavation of stream crossings involved locating buried stumps, boulders, logs, and black organic rich soil as indicators of the natural stream channel.

The road bench at wet areas and seeps at stations 4+00, 4+50, and 16+00 was outsloped and fill was moved down the road to a dry, more stable storage location. Past projects have indicated that fill material should not be placed on top of springs or seeps because this can cause saturation of the fill resulting in slope failure.

The main difficulty with this road pull was the result of the numerous large old-growth redwood trees. The trees greatly limited excavator swing room and reduced available roadfill for recontouring, especially at station 24+50. Extra travel is necessary to fill the cutbank behind a giant redwood tree because the typical swing pattern is altered. Instead of the typical scoop, swing, and dump pattern, the excavator was forced to rake a large pile of material along with him while moving down the road to an area behind a large tree, or material was hauled up the road one bucketload at a time from sites up to 50 ft. away.

Road-to-Trail Conversion

Similar to road removal, a road-to-trail conversion involves excavating the roadfill from the outside edge and placing it against the cutslope to create a natural-looking, recontoured slope. The trail conversion involves leaving a 4-ft.-wide portion of the road bench to serve as the new trail tread. It is important to note that the excavator cannot simply deconstruct the road and then tamp in a trail tread. Rather, the trail tread must be located on a portion of the original roadbed. This allows the trailbed to be located on a previously compacted surface and eliminates the oversteepened trail cutbank that would be created if the trail were recut into the fully recontoured material.

The lower portion of this project involved the reconstruction of 2,600 ft. of forest haul road into a gently curving hiking trail. The road removal took 84 hours over a nine-day period and included excavation of 2,445 yd.³ of roadfill and 280 yd.³ from eight stream crossings. The average production rate was 32 ft.³/hr. and 289 ft./day of road-to-trail reconstruction.

Stream crossings were excavated to recontour the natural channel shape, and an attempt was made to locate natural channel features. A Humboldt crossing with numerous large logs was removed to expose the active stream channel at station 13+00. The logs removed from this crossing were placed against the east streambank to provide armor from high flows. This streambank needed additional excavation to remove some perched fill, and the logs blocked a more desirable trail-crossing location. Two cubic yards of small angular boulders were placed as bed armor in each of the two larger stream crossings. The rock armor provided a low water crossing for the Sweco bulldozer to cross without sinking into deep mud. The road bench at wet areas and seeps was excavated similarly to a stream crossing by creating a gentle swale, and fill was moved down the road to a dry, more stable storage location.

Saving some trees on the outboard edge of the road allowed for the construction of a meandering trail on a previously straight road. Leaving the larger trees required that some of the roadfill remain in place. At these locations the trail alignment curved out and ran adjacent to the tree. To obtain material to replace the remaining fill, additional material was excavated in the reach between the trees. At these locations, the trail alignment curved toward the inside of the road. The problem with leaving trees in the fill slope is that excavation around the trees may leave them vulnerable to windthrow or uprooting. Only one week after this project, a tree was uprooted, leaving an undesirable mound of fill material perched above Squashan Creek.

Postconstruction Evaluation

Site Preparation

Additional site preparation would have improved productivity of this project. In the road-removal area, a few large redwood logs were bucked up to allow the excavator to move. These logs needed to be cut into shorter sections because they were difficult to move. One redwood log took almost one hour to push down the slope and out of the way.

Historical and Cultural Resources

Evidence of old corduroy roads exists throughout Squashan Creek. These roads were used in early logging efforts to skid logs using a team of oxen or a steam donkey (mechanical cable winch). The equipment for this project traveled over a short section of a corduroy road to access the upper road-removal section. The operator limited damage to this resource by carefully walking over the section and not doing any recontouring. Old logging cable and an old piece from a bulldozer were the only other evidence of historical resources found at the site. These items were left intact to the side of the road-reconstruction site.

Verbal communications with a member of the Yurok tribe indicate that the mouth of Squashan Creek was the site of an old Native American village. This project did not affect the area indicated, and no Native American historical artifacts were found.

Production Costs and Rate

The total construction cost for this project was $22,131.22 (see Table 2). This value was used to calculate a total average production rate for the project of $6.95/yd.³ (see Figure 3). The best production rate was $2.69/yd.³ during the road-to-trail perched fill removal. Production rates for crossing removal for both sections was $9.41/yd.³ The excavator averaged 31 ft./hr. or 289 ft./day.

Park Staff

Two trail crewmembers were onsite to assist with the project implementation. The main function of the crew was to transport fuel to the equipment. The crew was also responsible for removing rebar and dismantling old bridges. This crew was not motivated to work efficiently or provide additional help on brush removal.

Excavation

The road-removal section had complete excavation of fill material from the road bench. The crossing at station 5+00 in the road-removal section needed additional excavation from the left streambank.

The road-to-trail conversion had good excavation of fill material; however, a few areas should have had additional excavation. Some of the fill material left in place was the result of an attempt to protect standing trees, but these areas may have been better treated by removing the trees to favor complete excavation. The stream crossings had complete excavation; however, at the crossing at station 13+00, the active channel should have been aligned closer toward the middle of the valley.

Recontouring

The road-removal section had a complete recontouring except where springs or seeps were present in the cutslope. A complete match was obtained, including behind redwood trees where fill had to be carried in from nearby areas.

The access road between the two sections needed additional recontouring and ripping out of the old trail tread. This work was done at a fast speed but with extremely poor quality for a short distance.

The road-to-trail conversion had nearly complete recontouring except at station 21+00. This station had a large overhanging cutslope that was difficult to fill, causing the contractor to avoid completing the prescription here. The inspector should have caught this error at the time; however, it slipped by unnoticed. This area could have been fully recontoured with an additional hour of work.

Organic Material

Production data from the road-removal portion show that areas where brush removal had already been completed by park hand crews had higher production rates than areas with no prior vegetation removal.

The removal of standing trees and the handling of woody material took over 50% of the contract time (see Figure 4). This project had a heavy brush cover before construction began, and the excavated fill material was composed of 25% large woody material. In the road-to-trail conversion, trees and brush were pushed down into the surrounding forest. The project would have been improved if the excavator had pulled some of the logs back up onto the recontoured slope and placed them just below the new trail bench. Small herbaceous vegetation growing on the cutslope was left in place and buried under the recontour.

Collateral Damage

The old-growth redwood trees are the most valuable natural resource in the project area. The contractor and operator were strongly encouraged by the project supervisor and the project inspector to protect redwood trees at all costs. At the start of the project, the operator clearly understood the need to protect these trees from collateral damage and proved to be exceptionally careful when working close to them. Very little damage occurred to the bark and roots.

During crossing excavations, two active stream channels did receive some collateral damage. Both crossings were located in the road-to-trail portion of the project. The crossing located at 13+00 required removal of logs and fill from an active channel, which released fine sediment into Squashan Creek. The crossing at 01+00 was composed of sand and gravel and did not contribute much sediment to the stream.

Equipment

All three excavators used on this project were well sized and performed the job efficiently. The new equipment slightly outperformed the older Komatsu because of the hydraulic controls on newer machines. The new Komatsu performed at the lowest noise decibel, which is of importance when working in habitat for sensitive wildlife. The hydraulic thumb design on all three machines was slightly different. The new Komatsu had a cantilever design that allowed the greatest range of motion. The thumb on the John Deere had a range of motion that allowed it to strike the boom when in full open position. All three thumbs, however, allowed equipment to easily move and place woody material. The thumb can also be used to rake away material from the machine on an outswing.

The use of demonstration equipment provided an opportunity to see how various machines perform in difficult terrain. The demo equipment also saved the contractor money because he was able to use his machines on other jobs and did not have to pay for time on the new machines.

Two problems did arise from the use of demo equipment. The first problem was that the salesperson made numerous visits to the site to talk to the operator, causing delays in production. The second was that the large delays were caused by the move-in and move-out time when exchanging machines. Also, as a money-saving attempt, the operator wanted to leave the equipment with an empty fuel tank at the end of its demo period. This required a difficult fueling schedule, which involved shuttling fuel cans at less than optimal times. It also forced that equipment to end a half-hour earlier than needed because no fuel was available when its tank unexpectedly was empty. Ending a half-hour early left an oversized berm at station 00+00 adjacent to a stream crossing, which then required numerous hours in the Sweco to reshape.

Operator

Zeph Skeen, the sole operator on the contract, worked with great enthusiasm and interest in providing quality results. Skeen began the work by displaying the ability to travel through extremely narrow access routes while avoiding contact with live trees. He was very cautious about protecting old-growth trees and sensitive to travel through wet areas and worked with great skill and accuracy when placing material.

Recommendations for Future Work

Equipment Move-In

Prior to an equipment move-in, the contractor and operator should know the exact location where time paid by state parks begins. For this project, the contractor should have been notified that paid equipment time would begin at station 00+00 on the road-to-trail segment located adjacent to the water-filter tanks.

The contractor and operator should also understand that payments are not made for extraneous moves in and out to exchange equipment or make repairs. It is important that the operator, not just the contractor, understands contract specifications so he doesn’t feel cheated, therefore lowering his production or quality of work.

Site Preparation

It is more cost-effective to remove small trees and brush prior to heavy-equipment work. The excavator does have the ability to remove this material; however, a two-person swamping crew costs half as much as an excavator. Complete brush removal is not necessary, but as much standing material as possible should be removed so the excavator swing capability is not limited during recontouring. Felled trees should be bucked into 10- to 20-ft. lengths and piled up on the outside edge of the road. The downside of this method, however, is that trees that are cut and bucked have sawed ends that look less natural than trees that are snapped off by the excavator. Another concern with felling trees by hand is that the excavator then has to dig out the stumps. This does not seem to be a problem, though, because as the fill is excavated, the stumps can be removed easily.

Excavation

A potentially useful supplement to road-removal work would be an equipment operators’ rehabilitation pocket book. The inspector could go through the guidebook with the operator on the first day of the job to discuss techniques and specifications, and the operator could keep the book for reference. The guidebook could be written in general, easy-to-understand language describing important elements of road rehabilitation. The book could contain important graphics and numerous photos. The book could allow any good operator to be inspired and educated on the tricks of the trade. The book could also offer seasoned operators suggestions to fine tune and obtain perfection.

An additional requirement for contractors should be to have the operator attend a preproject hike through a previous road-removal or road-to-trail project. During this walk-through, the inspector can point out the successes and failures of a project. The inspector can ask how the operator would recommend repairing the problems. Or field trainings should take place twice a year in which the general public is invited to tour projects. A requirement in contracts could be that all operators have attended field training prior to working on a park construction job.

Marking chalk in a spray canister could be used to help operators visualize crossing excavations or road-to-trail alignment locations. Instead of arm waving and pointing at a rock or log, the contractor can directly mark the outer edge of an excavation on the road surface. This will reduce the possibility of misaligning a stream-channel excavation or underexcavating the crossing width. The markings will quickly disappear when equipment work begins and are intended more for visualization before excavation.

Organic Material

In this project the excavator worked around a large fallen log for an hour before he suddenly realized the log could easily be removed. Before trying to work around large, woody objects, it pays to try to move them first.

Limit the number of trees left in the fill slope. The problem with leaving trees in the fill slope is that excavation around the trees may leave them vulnerable to windthrow or uprooting.

Brushing—the collection, separation, and placement of organic material—should be analyzed to better understand how it affects production rate. It might be interesting to observe and record the number of bucket loads of organics moved per day. If possible, the project inspector should record the number of bucket loads of organic verses the number of loads of soil moved per hour at various points during the project. A more detailed approach would be to use a stopwatch to record the exact amount of time each task represents during the day.

Monitoring the rate of natural revegetation should take place to compare areas where thick brush mulch covers 100% of the soil with areas where very little mulch was placed. There may be some point at which the thickness of brush mulch inhibits revegetation. If it is determined that the volume of organic material inhibits revegetation, the material should be placed as a windrow along the base of recontoured slopes.

Collateral Damage

To reduce damage to water resources, active streams should be diverted through a pipe around crossing excavations a few days prior to removal. In this project, a 4-in. flexible drainpipe would have been sufficient to carry water around the construction site. Temporary stream-crossing designs detailed in Handbook for Forest and Ranch Roads, prepared for the Mendocino Resource Conservation District, could be consulted. Shredded redwood bark or redwood needles should be acquired, and an 8-in. layer should be spread across any surface to be temporarily filled over. This allows the equipment operator to easily locate the original ground surface during final reshaping. Geotextiles should not be used for this purpose because they shred easily and are difficult to excavate. Attention should be paid to regulations regarding this activity.

Both the project supervisor and the project inspector should emphasize protection of trees and vegetation during the initial walk-through. The contractor needs to be reminded about resource protection specifications, but more importantly the operator needs to be clear about what should be protected on the ground. This aspect of the Miners Ridge project was very successful and made a big impact on the operator.

Equipment

To avoid unnecessary downtime, heavy equipment should have a regular fueling schedule that keeps fuel tanks full at all times. Avoid running fuel down just because a machine is done with its phase of the project.

If weather or other variables limit the number of weeks available for construction, it may be beneficial to analyze options regarding speed of work around trees and brush. An operator can be required to use extreme caution working with brush and trees. A careful operator moves slower—costing the state more money—but will have less downtime as a result of hydraulic hose breakage. An operator encouraged to move fast dealing with brush might experience more downtime because of equipment damage, but the cost of downtime rests with the contractor. Downtime from equipment damage may extend the project time frame more than the slower speed of a careful operator.

Operator

On projects involving an hourly contract, great care should be taken when giving the operator and contractor a time line. If the operator thinks he is behind schedule, he might do poor-quality work in order to speed up production. If the operator thinks he is working ahead of schedule, however, he may be tempted to slow down production and stop more often to ask the inspector questions.

Also, before any work begins, the contractor and operator should go through the contract to review important sections. The operator needs to know what activities are not part of the paid time, such as breaks, fueling, and maintenance.

State parks need to continually work to improve project estimating and budgeting. A better understanding of production rates and the project time line will help the inspector understand any limits on perfection versus getting the job done. New or inexperienced inspectors need additional tools to help compare how a project is proceeding within the overall time line. The inspector should have a good estimate of construction hours and expected production rates.

Conclusion

The Miners Ridge Road-to-Trail Restoration Project greatly improved one of the most popular hiking loops in Prairie Creek State Park. The project eliminated unstable roads and reduced erosion hazards by reconstructing a road into a trail. The road-to-trail reconstruction greatly improved the function and aesthetics of the hiking system. The new alignment provides drainage to springs, seeps, and streams by using bridge structures over excavated crossings. The trail is completely outsloped and narrowed to reduce future maintenance costs. The park visitor now has an easy-to-hike, gently contouring, solid trail tread through a forest grove that previously had a muddy, overgrown, old logging road.