[2] The San Gabriel Mountains were first preserved by the federal government in 1892 as the San Gabriel Timberland Reserve, established by U.S. President Benjamin Harrison and influenced by California conservationists, Abbot Kinney and John Muir.

The following trails provide access: Hiking trails in the Designated Wilderness are built and maintained utilizing hand tools and materials which are strictly limited in terms of environmental impact.

The use of chainsaws to remove trees that are down across trails is prohibited, requiring the use of crosscut saws, block-and-tackle chains and ropes to pull trees off of trails, griphoists, and other mechanical tools which do not produce noise or petroleum-based pollutants.

Blasting to remove rock outcrops is prohibited, as is the use of fire-fighting tools like tractors, Phos-Chek air drops, Tovex Firebreak II explosives, and chainsaws to cut fire lines.

To achieve such an effect, tree limbs and branches that must be cut back are finished with an effort to appear natural, bucked tree trunks that are removed from the trail are relocated so that they appear at a distance and do not look to have been cut by people, and even sawdust from crosscut saws will be collected and buried off of the trail.