The Alpine Lakes is the largest wilderness area near the population centers of Puget Sound, counted at 414,161 acres (167,605 ha) following the 2014 expansion.

[2] The region and adjacent areas were being extensively used for mining, timber extraction, and fur trapping leading to roads, clear cuts and ecological degradation.

[3] In addition, there was much criticism by conservationists that recreational usage should not be exclusive to the upper alpine terrain as the regional forestry leadership advocated saving the lower forests for possible timber sales.

[3] After exhausting debates, public meetings and with even a request by the Forest Service to veto, President Ford signed the Alpine Lakes Area Management Act into law on the afternoon of July 12, 1976, reportedly saying "anywhere so beautiful should be preserved."

[6] Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to the various climate differences.

[7] In addition, small fragments of the oceanic and continental lithosphere called terranes created the North Cascades about 50 million years ago.

[7] During the Pleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris.

[4] Uplift and faulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the Alpine Lakes Wilderness area.

The Alpine Lakes Wilderness and its old growth forests offer critical habitat for many species on the Washington State Department of Fish and Wildlife's "Species of Concern" list which includes the Western spotted frog (Rana pretiosa), Common Loon (Gavia immer), Western Grebe (Aechmophorus occidentalis), Goshawk (Accipiter gentilis), Golden eagle (Aquila chrysaetos), Bald eagle (Haliaeetus leucocephalus), Peregrine falcon (Falco peregrinus), Merlin (Falco columbarius), Flammulated owl (Otus flammeolus), Spotted owl (Strix occidentalis), Vaux's swift (Chaetura vauxi), PIleated woodpecker (Dryocopus pileatus), Lewis' woodpecker (Melanerpes lewis), White-headed woodpecker (Picoides albolarvatus), Black-backed Three-toed woodpecker (Picoides arcticus), Horned lark (Eremophila alpestris), White-breasted nuthatch (Sitta carolinensis), Sage thrasher (Oreoscoptes montanus), Loggerhead shrike (Lanius ludovicianus), Vesper sparrow (Pooecetes gramineus), Sage sparrow (Amphispiza belli), Townsend's Big-eared bat (Plecotus townsendi), Fisher (Pekania pennanti), wolverine (Gulo gulo) and the Canada lynx (Lynx canadensis).

The wilderness offers exceptional water quality and holds portions, or all of, the headwaters for the Skykomish, Snoqualmie, Wenatchee, and Yakima Rivers.

The western end of the Alpine Lakes Wilderness is accessible via the Middle Fork of the Snoqualmie River northeast of North Bend, Washington.

Salmon La Sac north of Roslyn, Washington is a hub for trailheads and U.S. Forest Service roads providing entry into the southern and central regions.