One of the best sites for overnight tent camping lies probably half way (at 0.9 miles) through the roughly 1.9 miles to the summit. You gain an elevation of 1100 ft to the summit of Bachelor mountain and may take around 45-60 mins (times may vary). You witness Mt Jefferson upclose.
The trail offers views to the South Cascades, esp peaks to Mt Washington North & South Sisters, Broken Top, Three Fingered Jack, Mt Bachelor, as well as Mt Adams to the North.
There are two ways to get to the trailhead in the Santiam wilderness and one of the ways (FR 1168/430) is simply not meant for passenger cars, or you may just be relying on your luck. The other one is gravel with potholes and uneven patches in some sections. Please do your research. I may be an exceptionally good driver to have managed to escape without a broken axle. 😉 Moonlight camping offered a pretty sight.
2014 Update: Night camping in a cloudy setting
2016 Update: Enroute to Coffin Mountain