Either way, this trail has a brutal climb, made all the moreso by the 2011 fire. The subsequent erosion after the fire has made it even tougher. It's a simple loop with a couple side trail options. Some of the climb (either way) is unclimbable, so be prepared to hike a bit. The best route is todo the standard CCW route, then head back north on the road up toward the ski area and connect to the doubletrack that will take you back down the unclimbable climb, so you get a way cool, technical downhill. This is all easy to understand if you get the "Santa Fe, Bandelier, Los Alamos" map from Sky Terrain trail maps.
From Los Alamos, head south on Highway 501 aka Diamond Drive as if you were going to the Pajarito Mountain Ski Area. As you leave town, you will see a sharp right to the ski area--ignore it and go straight, looking for the first pullout on the right. The entry to the pullout is often deeply rutted, so you may need to park by the road. Follow the pullout a fey yards back to the north until it deadends--go through the gate and down to the bottom of the ravine. Look for the singletrack across the ditch to take the loop CCW (recommended) or go straight up the wouth side of the ravine for a CW loop.
http://www.singletracks.com/item.php?c=1&i=5597