Described by Wuerthner as a "rocks and ice wilderness," much of the Mount Washington Wilderness consists of lava flows and rubble. However, it does include some forested areas with stands of lodgepole pine, and there are 28 lakes in the northern and southwestern parts of the space. Vegetation in the Mount Washington Wilderness includes mountain hemlock, lodgepole pine, ponderosa pine, and whitebark pine. Ponderosa pine occurs at the eastern base of the volcano, with Douglas fir on the western side. On rough surfaces covered with lava, vegetation is less common, but there are some flows, including young lava flows, with trees growing on them. Mountain hemlock also grows on lava flows, and there is an understory of beargrass, huckleberry, and rhododendron. Animal life includes large animals such as deer and elk, with the rare American black bear or cougar. There are small animals in the Mount Washington Wilderness like pikas, marmots, martens, snowshoe hares, and ground squirrels. Lakes in the wilderness sustain populations of brook trout, cutthroat trout, and rainbow trout, and frogs can be observed around some of them.
Recreation
The Mount Washington Wilderness lies near the Willamette Valley, which is heavily populated. While the area is not used as frequently as many other wilderness areas in the Oregon branch of the Cascade Range, it offers scenic lakes and trails. These include volcanic features such as lava flows from Mount Washington and Belknap Crater. Permits have been required for visitors since 1991; they are offered for no charge after Memorial Day through October 31. Motorized and mechanical equipment like drones or bicycles are prohibited. Visitation to the wilderness has declined since the mid-1990s but leveled off after the B&B Complex fires in 2003. Surveys suggest that about 50 percent of visitors to the Mount Washington Wilderness do not make campfires, a lower rate than other nearby wilderness areas. Additional surveys suggest that about 82 percent of respondents who come to the wilderness area to camp do so within of a lake. There are forest roads which extend to the base of Mount Washington. The Pacific Crest Trail is the major path through the Mount Washington Wilderness, extending from the northern to southern edge of the area. Traversing lodgepole pine forest and lava flows, the trail passes over the western side of Mount Washington. The hike is challenging, ranging in elevation from with little sources of water. Other trails include a loop around the Patjens Lakes, the Hand Lake trail, and the Benson Lake route. Friendly for families and children, the Patjens Lake trail runs for, only gaining in elevation. Water is abundant along the route, which passes through lodgepole pine forests with the occasional meadow. The Hand Lake and Benson Lake trails are also easy day hikes, lasting and, respectively. One of the trails within the wilderness area, known as the Dry Creek Trail, is not maintained by the United States Forest Service and is no longer recommended as a hiking route due to fallen trees in fire-damaged forest. The U.S. National Geodetic Survey Data Sheet for Mount Washington notes that climbing the volcano is challenging and dangerous and thus is not recommended for inexperienced climbers or climbers without proper equipment.
Mineral and geothermal potential
A mineral survey from 1980 through 1981 detected little potential for metallic mineral or fossil fuel resources in the Mount Washington Wilderness. The area contains large amounts of cinder, more than, but there are alternate sources in the region, which are sufficient to meet local demands. Likewise, there are no mines in the area, nor any documented history of mining claims; the closest mines are located to the west in the Blue River mining district. The volcanic vents throughout the Mount Washington Wilderness are underlain by Eocene to Pliocene volcanic rock layers, which do not contain hydrocarbons for fossil fuels. While there is relatively little potential for geothermal energy in the High Cascades, there are hot springs along the western edge of the mountain range. The Belknap Hot Spring lies to the southwest of the wilderness area, ejecting water at a rate of per minute with a temperature of. The Mount Washington Wilderness has unknown geothermal potential as there have been few holes deep enough to assess its geothermal resources. Silicic bodies of intrusive rock are typically greater in size than more mafic rock in shallow crust, but geologically young, silicic rock does not occur within the Washington wilderness area.
