What to See in Mount Jefferson Wilderness - Top Sights and Attractions

Stratovolcano in Oregon. Mount Jefferson is a stratovolcano in the Cascade Volcanic Arc, part of the Cascade Range in the U.S. state of Oregon. The second highest mountain in Oregon, it is situated within Linn County, Jefferson County, and Marion County and forms part of the Mount Jefferson Wilderness. Due to the ruggedness of its surroundings, the mountain is one of the hardest volcanoes to reach in the Cascades. It is also a popular tourist destination despite its remoteness, with recreational activities including hiking, backpacking, mountaineering, and photography. Vegetation at Mount Jefferson is dominated by Douglas fir, silver fir, mountain hemlock, ponderosa pine, lodgepole pine, and several cedar species. Carnivores, insectivores, bats, rodents, deer, birds, and various other species inhabit the area.

Also known as Seekseekqua by Native American populations, the volcano was named after United States President Thomas Jefferson, and was first ascended by E. C. Cross and R. L. Farmer in 1888. It sits atop an area of crustal melting, and was produced by the subduction of the oceanic Juan de Fuca tectonic plate under the continental North American tectonic plate, forming about 730,000 years ago. Consisting of basaltic andesite, andesite, and dacite, the mountain has been extensively altered by glacial erosion. The surrounding area contains a number of other volcanic features like cinder cones, shield volcanoes, and tuyas (flat-topped, steep-sided volcanoes formed when lava erupts through a thick glacier or ice sheet). It is considered a low threat by the United States Geological Survey. Despite the low chance of future eruptions, many scientists still consider mudflows a major threat at Mount Jefferson.^[1]

Summit in Oregon. Three Fingered Jack is a summit of a shield volcano of the Cascade Range in the U.S. state of Oregon. Formed during the Pleistocene epoch, the mountain consists mainly of basaltic andesite lava and was heavily glaciated in the past. While other Oregon volcanoes that were heavily glaciated—such as Mount Washington and Mount Thielsen—display eroded volcanic necks, Three Fingered Jack's present summit is a comparatively narrow ridge of loose tephra supported by a dike only 10 feet thick on a generally north–south axis. Glaciation exposed radiating dikes and plugs that support this summit. The volcano has long been inactive and is highly eroded.

Three Fingered Jack has diverse flora, fauna, and fungi. The Molala people, one of the indigenous groups in the northwestern United States, historically inhabited the area around the volcano. Not much is known about Molala culture, other than that the group fished for salmon and collected berries, fruits, obsidian, and dried herbs. David Douglas was the first person of non-indigenous descent to reach the area in 1825, followed by Peter Skene Ogden the following year. The first group to ascend the volcano reached its summit in September 1923. Three Fingered Jack can still be climbed, but climbers can require rescue after becoming disoriented in low visibility conditions.^[2]

Lake in Oregon. Marion Lake is a subalpine lake located in Linn County of the U.S. state of Oregon. The lake is in central Oregon's Cascades within the Mount Jefferson Wilderness. The lake is approximately 300 acres, at an elevation of 4,134 feet.

It is the largest lake in an Oregon wilderness area and the largest lake not accessible by automobile. With the exception of large Waldo Lake, it is the largest natural lake in the Willamette National Forest on the west slope of the Central Cascade Range.

Marion Lake was named in 1874 by John Minto's Marion County road-viewing party in 1874. Marion County, in turn, had been named for General Francis Marion of Revolutionary War fame.

It is the headwaters of Marion Creek, a tributary of the North Santiam River.

The rough-skinned newt (Taricha granulosa) is found at Marion Lake during the amphibian's breeding season.^[5]