Soil Ecology and Research Group

last update January 31, 2004




The project area is located in the Little San Bernardino Mountains east of State Highway 62 and west of Joshua Tree National Park and is under the jurisdiction of the Bureau of Land Management’s (BLM) Palm Springs/South Coast Resource Area. It includes the southern half of Little Morongo Canyon, which empties into the Coachella Valley near the town of Desert Hot Springs. The project area lies within the Big Morongo Canyon Preserve Area of Critical Environmental Concern (ACEC), and serves as a wildlife corridor, lambing area and watering area for desert big horn sheep (Ovis canadensis nelsoni). The sheep migrate between their summer range in the San Bernardino National Forest/San Gorgonio Wilderness areas and their winter range in Joshua Tree National Park and other areas of the Little San Bernardino Mountains. Several year-round watering sites are located in the upper reaches of the canyon that are necessary for big horn sheep survival. The herd is estimated to consist of 50 sheep.

Southern California Edison (SCE) maintains a power line access road that runs through a portion of Little Morongo Canyon. The road is also popular among off-highway vehicle (ohv) enthusiasts as it is one of the few routes between Morongo Basin and the Coachella Valley. The SCE access road must remain open for maintenance operations; thus, BLM has no plan to close the road to off-highway activity. Over the past few years, however, unauthorized off-highway activity has begun to spread out from the authorized SCE power line access road. Numerous hill climbs and secondary trails up several side canyons are now developing, and the off-highway activity that is occurring is impacting both soils and vegetation in habitat that is critical for desert big horn sheep. If left unchecked, it could not only drive them from a critical source of water, but quite possibly inhibit their ability to migrate between their winter and summer ranges.


Scope of Work
The purpose of this project is to prevent off highway vehicles from entering the side canyons and/or roads adjacent to the SCE power line access road. Five trails (figure 1)


Figure 1. Location of off-highway vehicle trail closures in Little Morongo Canyon.


were identified for closure and are known as sites 1,2,4,6 and 7. These sites were initially visited on December 6, 2003 with Greg Hill, a Palm Springs BLM representative and Dee Zeller, a Big Morongo Canyon Preserve naturalist.

On 6 January 2004 Soil Ecology and Restoration Group (SERG) personnel returned to the sites to take measurements, obtain GPS readings and develop ideas on how to approach the project. It was decided that a combination of post and cable fencing and earthmoving would be the most effective means of deterrence. On January 29, we purchased and delivered 45 posts to Big Morongo Canyon Preserve for storage. Each post is made out of used railroad track, 5-feet in length, weighs 105 pounds and has a 1-inch hole near the top through which a 0.5-inch wire rope can be threaded. On 17-18 February, posts were installed the posts at sites 1,2,4 and 6, the side canyon sites. Posts were spaced 20 feet apart and span the width of the canyon at each site. Thirty pounds of concrete was placed at the bottom of each posthole to help anchor the post. Each post has a 6-inch strip of reflective tape on it to make it more visible at night.

On April 6-8, a New Holland 545D landscape loader was used to conduct earthmoving work at all the sites. Where applicable, mounds were built, trenches dug and boulders placed on the trails. The majority of this work was done near the post and cable fences and the power line utility road. Trails were ripped to facilitate the reseeding of native shrubbery, which should propagate from the existing seed bank. Cholla was planted on the mounds and in the ripped sections. After the earthmoving work was completed at each site, wire rope was stretched through the posts and clamped at the ends. A total of 900 feet of 0.5 inch galvanized wire rope was used at sites 1,2,4 and 6.

The following pages show pictures of each site (figures 2 – 21).


Figure 2. Site 1 before installation.


Figure 3. Site 1 during installation; setting the posts at 20-foot intervals.


Figure 4. Site 1 during installation; building mounds near the post and cable fence.


Figure 5. Site 1 during installation; clamping down the wire rope.


Figure 6. Site 1 after installation; post and cable fence and mounds on trail.


Figure 7. Site 2 before installation.


Figure 8. Site 2 during installation; building mound at trail entrance.


Figure 9. Site 2 after installation; wire rope stretched across the trail.


Figure 10. Site 2 after installation; post and cable fence spanning the canyon floor.


Figure 11. Site 4 before installation.


Figure 12. Site 4 during installation; building mounds and reestablishing boulder barrier.


Figure 13. Site 4 after installation; Cholla planted on the mounds and ripped trails.


Figure 14. Site 4 after installation; trench dug across entrance to canyon


Figure 15. Site 6 before installation.


Figure 16. Site 6 during installation; trench being dug across entrance to canyon.


Figure 17. Site 6 after installation; wire rope stretched across ripped trail.


Figure 18. Site 6 after installation; trail blocked at SCE power line access road.


Figure 19. Site 7 before installation.


Figure 20. Site 7 during installation; building mounds on ripped trail.


Figure 21. Site 7 after installation; overview of ripped trails.


Conclusions and Recommendations
Slightly over one month after completion of the project, SERG personnel revisited the area to determine and map additional sites that needed to be closed in the future and to check on the current sites. All sites were intact with the exception of Site 1. All the berms that had been constructed were knocked down and smoothed out or new trails were established by driving around them. It appeared that someone had pulled out the end post, tied it to a heavy-duty truck, and subsequently pulled out all the remaining posts, with each cement ball in tact, and dragged the entire entity downstream about 100 feet downstream (Figures 22 & 23).

The goal of this project is to protect the endangered big horn sheep from disturbance while continuing to provide off-highway recreational opportunities. Current work was concentrated in the southern half of the Little Morongo Canyon section of the Big Morongo Canyon Preserve Area of Critical Environmental Concern. Future work within the preserve is still needed in the Little Morongo Canyon. This includes efforts to close off the canyon to southbound OHV traffic just south of Morongo Lakes. This would protect the canyon from a mile and a half of OHV traffic before reaching the barrier constructed at site 1. Since vulnerable slopes are potential erosion hazards, it is necessary to identify hill climbs and staging areas within Little Morongo Canyon that should be closed. Closing would be accomplished by hand pitting, the addition of vertical mulch, debris scattering (using both dead plants and boulders) and the use of a biodegradable erosion control material, such as jute. The hill climb sites were surveyed on May 13, 2004. Locations are shown in figure 24. Four hill climb sites were chosen for restoration and will be called sites 8,9,10 and 11 (figures 25-28).

At the Big Morongo Canyon Preserve eastern boundaries, it would be necessary to minimize access to Joshua Tree National Park. For example, a canyon with no name (Canyon Sin Nombre), which allows access to Joshua Tree National Park, is present where the SCE powerline access road connects to the Kickapoo Trail near the town of Yucca Valley.


Figure 22. Post and cement ball pulled out of the ground by vandals.


Figure 23 Post and cement ball dragged downstream by vandals.


Figure 24. Locations of future worksites along the SCE powerline access road.


Figure 25. Site 8 hill climb.


Figure 26. Site 9 hill climb.


Figure 27. Site 10 hill climb.


Figure 28. Site 11 hill climb.


Within the ACEC, barriers need to be constructed in two places. First, along the northwest boundaries of the ACEC, where it interfaces with the town of Morongo Valley, and second, at the southern boundary where it crosses Big Morongo Canyon. The barriers would be constructed using the same methods as the current project. However, along with direct transplants of available cholla cactus, more species of native shrubs and trees should be planted to help repair and protect sensitive areas, including mesquite (Prosopis glandulosa) and bladderpod (Isomeris arborea). Wire cages (reinforced mesh) with T posts and treeshelters should be used to protect against herbivory and vehicle damage in sensitive areas. “Area closed” signs with “Big Horn Sheep Protection Area” emblems on them should be placed at all worksites.

Also, it would be beneficial to conduct a cleanup of the canyons to collect trash and other debris that can be removed without the use of a winch or crane. Work with the local off-highway vehicle clubs to remove larger items, such as abandoned cars, could be coordinated.

Furthermore, for both current and future projects, it is suggested that a quarterly monitoring, maintenance and irrigation schedule be arranged for a period of one year. At the end of one year, a Final Report would be due.

Proposal (July 7, 2000)