There is a really nice trail guide from Santiam State Forest that I am going to link to and spare you the driving directions and details:
http://www.oregon.gov/ODF/northcascade/ ... ckyTop.pdf
Basically, head up to Niagara (40 miles east of downtown Salem), turn left on Niagara Heights Rd and follow the signs 6.6 miles to Natural Rock Arch TH, 2 more miles to Rocky Top TH. The road is in really good shape, especially up to the Natural Rock Arch TH. The last 2 miles to the Rocky Top TH are a little bumpy but still passable in my Chevy Prizm.
Each trail is 1 mile total, with 500 ft elevation gain on the Natural Rock Arch trail and 700ft elevation gain on the Rocky Top trail.
Starting out at Natural Rock Arch TH The trail dives down quickly allowing a few views of the Santiam River drainage. A quick arrival at the arch; the vine maples really made a nice splash of color. Some interesting and enlightening views to be had here

http://en.wikipedia.org/wiki/Rocky_Top
Arriving at the trailhead I was greeted by this view to the North and the classy TH sign I had been keeping an eye on the forecast and knew that all I needed to do was get above the fog. Well, I was rewarded on the ascent of Rocky Top. Moving up, I was greeted by a dog, a Rhino, and some superb views. I don't think these are good for eatin', but I see the evidence of something better up ahead in red! Here we go, huckleberries ready to fall off the vine! In all seriousness, there were a lot of berries, granted a few were overripe and chewed up, but plenty for all! One more post should wrap things up...