The disjunct Mesic Forest Zone ecoregion is characterized by a dissected, volcanic plateau and mid-elevation mountains containing the highest forested areas in the Blue Mountains, western Wallowa Mountains, and western Seven Devils Mountains. Elevation varies from 4,000 to 7,700 feet (1,219 to 2,347 m). The climate is influenced by maritime air traveling up the Columbia River Gorge, with higher precipitation than other forested regions in the Blue Mountains. Snow persists late into the spring. The ashy soil holds moisture during the dry season and supports a productive spruce-fir forest. The region's boundaries correspond to the distribution of true fir forest before the modern era of fire suppression and high grade logging. Cold slopes feature subalpine fir, Engelmann spruce, mountain hemlock, lodgepole pine, big huckleberry, grouse huckleberry, Utah honeysuckle, sidebells pyrola, roundleaved violet, and northwestern sedge. Cool moist slopes feature grand fir, western larch, queen's cup beadlily, and prince's pine. Drier slopes feature Douglas-fir, ponderosa pine, Rocky Mountain maple, ninebark, pinegrass, elk sedge, and bigleaf sandwort. Lower, drier sites support ponderosa pine. The region covers in Oregon, in Idaho, and small areas in Washington, including parts of the Malheur, Ochoco, Umatilla, and Wallowa-Whitman national forests, and significant portions of the Mill Creek, Bridge Creek, Black Canyon, Monument Rock, North Fork John Day, North Fork Umatilla, and Eagle Cap wildernesses.