Snail Trail Phase 1: Road-to-Trail Conversion and Maintenance
Swasey Recreation Area, Bureau of Land Management (BLM), Redding, CA.
Many have speculated about the origin of the name Snail Trail, but few actually know the story. The name was given by the BLM trail builders who designed and built the trail due to the fact that the alignment was largely determined by the presence of Monadenia troglodytes, or the Shasta Sideband Snail. In order to protect the habitat of this species, the builders had to weave the trail along a narrow ridge, at grades above what is considered sustainable today. The builders were also limited to using an old forest road for a short section at the beginning of the trail for the same reason, and although the beginning of the road wasn't steep, it quickly became so and over time rutting began to develop along the trail tread, creating a channel for water to flow and initiating a process of steadily increasing erosion.
Looking to improve both the quality of the trail experience for mountain biking, and the sustainability of the trail, the Redding Trail Alliance (RTA), in cooperation with the BLM, and with assistance from Trail Laboratories (TL), mobilized on a road-to-trail conversion and maintenance project. Over the course of two site visits, RTA and TL staff identified and flagged maintenance locations along middle and lower sections of the trail, and put together a design and construction plan to transform the road into a section of trail that was not only sustainable, but also offered a new trail user experience for mountain bikers not offered on many trails around the area. The road section presented a unique challenge due to a combination of steep alignment, steep hillslope, and inability to move the trail off the road. The clear solution became, 1) meander the trail, and 2) control the speed of mountain bikers by building a series of consecutive berms which rewarded riders with a fun experience if they kept speed in check.
Converting the road into a trail was done through the adaptation and application of Best Management Practices (BMP's) commonly used for road decommissioning in forestry, but modified to create riding features that are enjoyable for mountain bikes. For example, a common BMP in forestry for this situation would be a cross-drain, or more commonly known, a waterbar. Although this technique works to divert water off the road/trail, it's offers a low quality trail experience for users. We took the cross-drain concept and then modified it to create either a roller, jump, or berm; a technique that meets the hydrologic goals of a cross-drain, but provides an enjoyable trail experience for users. During the conversion process, we carefully and specifically build each roller/jump/berm to direct the flow of surface water off the road/trail, but do so in a way which appears to only be for the purpose of creating a riding feature, not a drainage feature.
After completing the road-to-trail conversion section of Snail Trail, we moved onto the good stuff; improving the existing trail. We exited the road-to-trail section with one of the larger, if not largest berm on a trail in Northern CA. This thing was a beauty to build as the location had great soil. We applied a newer technique to the inside of the this berm, which we picked up during the Enticer Trail build last winter. For this, we trench the inside of the berm and then use rock from the excavation and surrounding area to construct a rock armored drain. It works beautifully and ensures that water gets off the berm quickly, but doesn't scour out the inside drain.
Moving downhill from the road-to-trail conversion section below the big berm, we sought to lengthen the trail wherever possible in order to reduce the overall grade. This was done primarily through meandering, moving the trail side-to-side across the original alignment and adding large berms to reducing braking and control water flow. In addition to these techniques, we also added rolling grade dips/grade reversals where needed, and improved anything that appeared to be degrading or not functioning properly (both in terms of environmental sustainability, and recreational enjoyment). After 2 weeks of work, we made it half-way down Snail Trail, improving all of the major erosion issues, and the overall experience of the trail significantly.
Phase 2 of the project will be completed in the Spring of 2018 as soon as soil moisture conditions are ideal for construction.