Icehouse Trail
The Icehouse Trail runs down a sloping mesa on the skirts of the Pine Valley Mountains just west of Washington. It can be done as an 18-mile loop, or as a 6-plus mile shuttled downhill. Top altitude is 5100 feet, lowest 3100. The Icehouse Trail itself is 6 miles of almost non-stop downhill, descending 2000 vertical feet. There are occasional very short climbs to keep you honest. Intermittent pumice bounders in the trail surface raise the overall tech level to upper-intermediate, but the final 1/3-mile plunge off the mesa is advanced technical and requires good skills.
Loop ride, from T-Bone Trailhead:
0.0    North (uphill) on road N37 08.430 W113 33.982
0.7    Pass water tank (return path north of tank)
N37 09.056 W113 34.032
2.6    Fork L on main road N37 10.592 W113 34.059
6.3    Pass Broken Mesa TH (keep L)
N37 13.398 W113 34.439
6.8    Through dip
7.3    Keep R N37 13.891 W113 33.866
8.6    Fork R (Critical Fork!) on smaller DT
N37 14.390 W113 32.706
9.8    Fork R toward gate (150 feet away)
N37 13.715 W113 31.948
9.8    Stepover to L of gate is trail
N37 13.699 W113 31.961
13.1  Broken Mesa joins on R, keep downhill
N37 11.625 W113 32.168
14.9  Begin plunge off mesa
15.5  R on Power Line trail N37 10.038 W113 31.703
17.9  L down road N37 09.056 W113 34.032
18.5  Back at parking
Getting there, loop ride: From the St. George Blvd exit of I-15, turn towards the city (west), then immediately turn right on 10th East. Zero your odometer here. Take the next right on Highland, then next left onto Industrial Road. Turn left at 0.7 on Red Rock Road. The road will turn to gravel. Keep left at the next fork, continuing north uphill on Cottonwood Road. At 2.6 miles, you'll see the T-Bone trailhead parking on your left. Park here and begin by riding up the road the way you were going.  (Alternate: At 3.3 miles, you'll pass a water tank on your right. The return trail for the loop option comes back here. You can park here for a slightly shorter ride.)
Driving route to the top: To reach the top for the shuttled ride, start out as above, but keep going up Cottonwood Road. The pavement ends at mile 3.7. Keep left at the next fork at 5.4. At the sign "Red Cliffs Mesa Rim Trail" at mile 8.8, keep straight (left) on the main road. You'll cross the forest boundary, drop through a wash, then reach a fork at mile 9.8. Keep right. The road gets rougher. At mile 11.3, a smaller doubletrack forks right, signed 092. If you have high-clearance 4-wheel, you can drive 1.2 miles further to the singletrack trailhead. Otherwise, quickly find a spot to park and begin riding the doubletrack southeast. Watch for the right fork at mile 1.2 with the stepover to the left of the gate.
Shuttle parking: Leave a car on Buena Vista Blvd, just off I-15's Exit 10 in Washington. Head southwest to the mountain that marks the entry to St. George. Turn right on Red Rock Road and head uphill to the top of the trail. To get back to your car, drop down the mesa as described above, but turn left on powerline doubletrack, then right at second pole to find a trail heading south. Then work your way downhill through the golf course and into town.

Copyright 2011 Mad Scientist Software Inc. Trail conditions change. Use this trail guide at your own risk.