The San Gabriel Mountain Trail Builders build hiking trails and perform repairs and maintenance on trails in an effort to limit the human environmental impact in the San Gabriel Mountain chain.
In areas where humans hike, bicycle, picnic, and camp, the lack of established, professionally developed trails results in a number of unplanned trails that are almost always dangerous since they take a direct route from parking areas to rivers. Numerous unplanned trails caused more extensive erosion to microenvironments and cause some spreading out of litter that gets dumped along the trails.
Full article: Dumpster Recovery in San Gabriel Mountains by Fredric L. Rice
Dumpster Recovery in San Gabriel Mountains