The area where the Marble Mountains now exist was once part of the flat bottom of an ancient, shallow ocean.

Millions of years ago, violent volcanic upheavings and the erosive cutting action of rivers and glaciers combined to form the Marble Mountains.

The Marble Mountain Wilderness features an unparalleled diversity of plant life found nowhere else in the state.

These trees include the Brewer's spruce, incense cedar, Western Juniper; white, subalpine, and Shasta red fir; Engelmann spruce, mountain hemlock, Pacific yew; and whitebark, knobcone, foxtail, lodgepole, sugar, ponderosa, and Western white pine.

The Marble Mountains form part of the drainages of the Salmon, Scott, and Klamath rivers.