To the east of Breitenbush [1], and almost directly north of Mount Jefferson [2], Olallie Lake is one of the nicest camping and hiking getaways in the area, with superb views of Mount Jefferson from the lake.
The lake has a small cabin resort (www.olallielakeresort.com [3]), which was closed and undergoing some badly needed cabin rebuilding in 2009 with plans to reopen in summer 2010; see the website for rates. The resort also manages the Paul Dennis campground adjacent to the cabin area ($14 campsite, $50 yurt) and rents rowboats and canoes.
Olallie Lake is along the Pacific Crest Trail, and there are hiking trails galore, many leading to other small lakes. In the early summer, wildflowers are an attraction; late in summer, this is a great place to pick wild huckleberries. The season up here is pretty short—snows usually keep the resort closed until July.
From the Detroit area [4], head north and east on Forest Service Road 46, then turn right on Forest Service Road 4220 (a rough gravel road) and follow it 13 miles to the lake.
Links:
[1] http://www.moon.com/destinations/oregon/the-willamette-valley/salem/excursions-salem/breitenbush-hot-springs
[2] http://www.moon.com/destinations/oregon/the-willamette-valley/salem/excursions-salem/mount-jefferson
[3] http://www.olallielakeresort.com
[4] http://www.moon.com/destinations/oregon/the-willamette-valley/salem/excursions-salem/detroit-lake