Black Butte is a stratovolcano (not a cinder cone, as many think) that is 5.5 miles west of Sisters, Oregon, off of Highway 22. Black Butte looks young, as it is barely eroded (except for little gullies a little bit above the base that were carved by long-gone streams). Mount Washington, which is visible from the summit of Black Butte, looks much, much more eroded, and older, than Black Butte. However, Black Butte is significantly older than Washington (Washington was partly eroded by glaciers, but Black Butte was too far east of the Cascade crest that it was unable to support glaciers, so erosion is minimal).
There is a well-graded trail up Black Butte (the trail starts halfway up the mountain, however). The trail is 3.8 miles round-trip. From the summit, one can view the Three Sisters (the view of the North Sister is great), Mount Washington, Three Fingered Jack, Mount Jefferson, Black Crater, and, on clear days, Mount Hood. The trail up Black Butte is very popular, and there is a staffed lookout on top.
Turn off Highway 22 on the Green Ridge Road (5.5 miles west of Sisters and 2.5 miles east of Black Butte Ranch). Follow Road 11 north for about 4 miles, and then turn left onto Road 1110 (gravel) for 5.1 miles to a parking area at the end of the road. This is the Black Butte Trailhead.
A Northwest Forest Pass is required to park at the trailhead or near the trailhead. Once at the top, do not climb or enter the cabin or the lookouts. The 85-foot lookout tower has been declared unsafe, and the cabin is the private residence of the lookout staff (which means to stay out).
Bring lots of water, for there is none along the trail, and it gets very hot and dusty in the summer and fall.
Camping is not possible along the trail (and it is not necessary, either). If you want to spend more than just a day in this area, however, check out Black Butte Ranch. It is definitely not rugged, but if you enjoy great food, great lodging, and great golf with mountain views, this is the place to stay.
The trail is open from June to November. In order to avoid crowds, climb in June or September-November. In July and August, as many as 100 people per day climb Black Butte.