Trail 1 at Cline Butte is accessed by climbing the forest road from Cline Falls Rd. to the summit of the tallest (southernmost) butte. You can also climb up the XC trail for a more single-track route to the junction.
Starting at the summit, the trail quickly drops over 700′ in under a mile. The turns are steep, loose, and most include a black-diamond garden of sharp rocks that has to be negotiated (or walked) — a dropper post is probably mandatory unless you’re some kind of psycho. Knee pads are good idea too.
Once you cross Trail 2 (which is an option from here if you like big dirt-jump doubles) you can fly down some single and double track back to the forest road for another lap.
This trail is maintained by Central Oregon Trail Alliance.