Holy Cross is really good..but it has some fairly technical scrambles, go with a friend. Also, check with corresponding NFS to make sure the trails are still open. A quick shot down to Buena Vista will get you to Chinaman Gulch and 7 mile, which are open year round. 7 mile is a easy cruiser, but it does take you through some private land, don't cut their gate if it's closed, turn around and just explore. There's a few spurs and campsites scattered everywhere along the trail. Chinaman's Gulch is pretty challenging and best done with a friend for spotting and recovery. Off of Chinamans is Carnage Canyon which is best avoided unless your rig (and wallet) are dialed in. You're almost guaranteed damage.