Beginning on June 17th, 2015, the Lake Fire burned parts of the San Bernardino National Forest, the San Gorgonio Wilderness, BLM land, and private land tracts in Southern California. Source documents can be found here.
A good overview of the after burn situation can be found here, in the Burned Area Emergency Response Assessment (BAER) Power Point Presentation.
Below are excerpts from the full Lake Fire Burned Area Report regarding Trails:
Trails: 37.6 miles Roads: 25.6 miles (NFS)
Emergency conditions exist for specific trails and sections of trail within the burned area. These emergency conditions are based on threats associated with anticipated post wildfire impacts on trails and trail users. Threats to trails include excessive erosion of the trail tread caused by interception and diversion of runoff from steep burn hill slopes. Trails may also be impacted where they intersect with drainages and crenulations.
Approximately 1.1 miles of systems trails are in high burn severity areas with 10.1 miles in moderate burn severity areas (due to topography and post-fire conditions moderate severity is estimated to have a high watershed response). Approximately .32 miles of Pacific Crest Trail (PCT) is in moderate burn severity. Life and safety of trail users is also at risk in some areas within the burn. Specific trails and sections of trail at increased risk from post wildfire threats are the South Fork Trail, Dollar Lake Trail, Aspen Trail, Fish Creek Trail, and sections of the Pacific Crest Trail and Santa Ana River Trail.
This determination is based on professional judgement and field based identification of segments of trail where implementing treatments would effectively lower the risk of major and trail damage, thus a favorable benefit to cost ratio was determined. Also based on professional judgement and field review, the BAER Team recommended against treatments for Lost Lake trail based on concerns for treatment effectiveness and an unfavorable benefit to cost ratio.
Trails – Storm proof trails and close portions of them to the public, as warranted, until properly stabilized.
Trail Storm Proofing:
Prior to the first damaging rain events and within the first year following the fire, storm proofing is recommended to minimize erosion of the trail tread. Storm proofing treatments, implemented with hand-tools, would include out-sloping, de-berming, water-bars, armored crossings at ephemeral drainages, and other suitable treatments outlined in the BAER Treatments Catalog to protect the trails from accelerated post fire flows and soil erosion. South Fork Trail, Poopout Hill Trail, Dry Lake Trail, Dollar Lake Trail, Camp Trail-spur, Aspen Grove Trail, Fish Creek Trail and sections of the Pacific Crest Trail would be treated. Repairs are recommended for at least least 25 miles of trail within high and moderate soil burn severity where high watershed responses are anticipated.
The inspectors would repair and maintain storm proofing treatments by correcting minor expected problems. Information gathered during these site visits may also be used to submit an interim funding request to the region. This treatment would be applied in the same zones of concern identified in the trail storm proofing section, above.
To protect trail user life/safety, closure of the area until after the first winter following the fire is recommended. Following the first winter, the trail and watershed conditions should be evaluated to determine if hazardous conditions still exist. Closure would be implemented through the issuance of a forest order or area closure and trailhead signage.