In 1937 Paramount filmed on location at the Red Hills area the motion picture North of the Rio Grande (1937) starring William Boyd as 'Hopalong Cassidy'.

The Red Hills Management Area is located within the western tectonic block of the Sierra Nevada metamorphic belt.

Within this block are Upper Jurassic volcanic and sedimentary rocks of island arc derivation which were highly deformed and weakly metamorphosed during the Nevada orogeny.

[2] The Management Area includes much of the Tuolumne ultramafic complex, one of the largest exposures of serpentine rocks in the Sierra Nevada metamorphic belt.

The dunite intruded into andesite pillow breccias and flows of the Peñon Blanco volcanic formation, which crops out near the northeast and southern boundaries of the Management Area.

The fault zone is on the southwestern boundary of the Management Area, and is believed to have once penetrated the Earth's crust down to the mantle, a probable source of the peridotite.

[2] Other geologic features of the area include northeastward trending dikes that consists of massive, dark brown, hornblende-plagioclase diorite which intruded into the dunite bedrock.

[2] Tertiary and Pleistocene alluvium consisting of sand, gravel, pebbles, and cobbles has accumulated in Six Bit and Poor Man's Gulches in the northern and eastern portions of the Management Area.

Important native perennial species include California oniongrass (Melica californica), big squirreltail grass (Sitanion jubatum) and pine bluegrass (Poa secunda).

[2] Herbaceous plants provide a spectacular wildflower bloom in the spring that attracts tourists, amateur naturalists, and classes from educational institutions.

[2] In the Red Hills buckbrush and other shrubs provide browse and seeds for small populations of mammals, including mule deer, jackrabbits, rodents.

Some common species include mourning dove, acorn woodpecker, ash-throated flycatcher, scrub jay, wrentit, plain titmouse, bushtit, Bewick's wren, and house finch.

Wintering bald eagles roost along the shores of Don Pedro Reservoir and have been observed where Six Bit Gulch enters the lake.

As many as 20 bald eagles have been sighted during the winter on the shores of Don Pedro Reservoir, roosting in stands of foothill pines.

During the dry part of the year the fish are confined to these permanent pools surviving in warm shallow water until spring when they move upstream to spawn.

The placer gold produced from this district was recovered by ground sluicing and hydraulic mining in earlier years, and by dragline dredging in the 1930s and 1940s.