Tire Mountain is a must-do route. It's got amazing scenery, an epic descent through a huge pine forest and narrow singletrack throughout. The trail is best ridden from Alpine to Cloverpatch.
The upper end of Tire Mountain starts from Alpine, just after the big open meadow view. The trail climbs quickly and steeply from the intersection and then descends into a thick forest of oaks and green, lichen covered boulders. The route climbs gradually overall with short ups and downs.
After the beginning sections of the trail, the views open up to steep grassy hillsides with rock cliffs and fins. You'll traverse this for a bit and feel like you're in the Highlands of Scotland.
As you dive back into the lush forest, the big descent begins. It's quite possibly the biggest pine forest you've ever seen. It's fun fast, and sustained with several turns and switchbacks.
The bottom reaches of the trail roll little less steeply. Look for an intersection with Cloverpatch on the left as the route makes a big left turn around the nose of a slope. Continue straight (right) if going to USFS Rd 124.