At Tunnel Canyon south of Tijeras, two parallel trails provide an easy 4.8 mile long loop hike. The route is obvious, well-groomed, and not especially rocky, with moderate grades. The area is juniper-piñon woodland, providing dappled sun and shade. Given the elevation (6590 to 7220 feet), this is a great choice for the fall or spring.
What you won’t find on this hike is solitude. The trails are heavily used by both hikers and mountain bikers. The parking area is small and may overflow.
To reach the trailhead, drive east on I-40 to the Tijeras exit. Where the exit splits, bear right. Head south through Tijeras on NM 337. About 2 1/2 miles south of I-40, the turnoff to the trailhead is clearly marked. Turn right to park, at 35 deg. 2.797 min. N, 106 deg. 22.986 min. W.
To begin the hike, head past the boulders at the end of the parking area. Sixty meters later, the loop option begins. Continue straight on the Tunnel Canyon Trail (5145) and do the loop clockwise, or turn right onto the Birdhouse Ridge Trail (5411) and do the loop counterclockwise. Here I assume you’ll choose the latter. You’ll find yourself on a trail that more or less parallels the bottom of Tunnel Canyon, up on the adjacent slope. At first you head more or less south; eventually the trail bears more to the southeast. The higher you go, the better the views become. On a clear day you'll be able to glimpse the southern Sangre de Cristo Mountains.
At 35 deg. 1.774 min. N, 106 deg. 22.934 min. W, you’ll encounter a trail marker where the Birdhouse Ridge Trail ends at the West Ridge Trail (5268). Turn left (northeast) to follow the West Ridge Trail down a local ridgeline. About 500 meters later, a trail marker indicates where the West Ridge Trail ends at the Tunnel Canyon Trail. Turn left (west) and follow the latter trail as it heads over to Tunnel Canyon, then drops to the canyon bottom. From there the trail heads downstream to take you back to the parking area.