Horse Ridge is about 20 miles east of Bend on BLM land and offers some excellent riding. Probably the main reason it is not more popular is the distance from town. The ride is through an open juniper forest on the north side of an east-west ridge. The views are excellent for much of the ride including Bend and the Cascades. This is a common off season destination mostly because it is out in the desert and has little snow but Palm Springs it's not. It is usually windy so wind protection is recommended in the off season. Although most of the trail is relatively smooth dirt, there is a fair amount of good technical riding in rocky sections. The lower flanks of the ridge can get sandy. More than one person has reported turning around from the lower trailhead because of the sand, but press on it gets much better!
There are a couple of options on where to start that will effect the difficulty and length of the ride. If you start at the east end of the ridge there is relatively little elevation gain or loose sand, but experienced riders may find the ride a little short. If you start at the bottom of the ridge, there will be a climb to the ridge either switch-backing up the trail or taking the old highway east to the east end of the ridge. The initial climb from the lower parking area is about 1000 feet. The upper portion of this trail is rocky and technical. If you have riders of different abilities and conditioning, it is a short drive to drop someone off at the east end of the ridge.
Getting to the lower main unofficial trailhead:____ In Google Maps copy and paste "Horse Ridge Frontage Rd @43.94443, -121.03313" as a destination. This is an unsigned trailhead so a map or GPS coordinate may be a good idea. Do not count on other riders being parked at either trail access point.
Getting to the east end trailhead:____ In Google Maps copy and paste "County Rd 2015/Fort Rock Rd @43.905600, -120.997000" as a destination. From here double back on the old highway about a hundred yards to the top of the first rise. The old highway at the top is not in Google maps but the actual gps coordinate is 43.90931, 121.00277 Again, this trail access point is not signed and this one in particular is hard to spot. There are currently are some rock carnes, but they may or may not be there when you show up.