This is primarily a winter riding area due to the sandy soils. Winter rain and snow doesn't hit this area as hard, and trails are often prime in the winter months.
Boyd Cave is a short trail (less than a mile) which takes you to Coyote Loop Trail at the road crossing to Arnold Ice Cave trail. The trail starts on a gravel road that leads you to the entrance to Boyd Cave (100 yards away) which is a nice detour and one of many natural lava caves in the area East of Bend.
This trail is maintained by Central Oregon Trail Alliance.