Dead Cow Loop
The Dead Cow Loop is an "adventure ride." You'll have mountain bike experiences you'll find nowhere else. For example, you'll be riding the slickrock bottom of a slot canyon through running water. The Dead Cow Loop is on BLM land in the desert south of Green River. The ride I describe here is a lariat of 16 miles with 1700 vertical feet of climbing.
Copyright 2013. Trail conditions and alignments change. Use at your own risk.
Riding notes, lariat loop from Red Rim:
0.0     South on Red Rim trail
N38 45.872 W110 02.341
0.6     Keep R N38 45.633 W110 02.748
1.2     Fork R N38 45.485 W110 03.279
1.9     Fork R down wash
N38 45.660 W110 03.593
4.2     Keep R (L = Ten Mile)
N38 44.356 W110 04.105
4.3     R into Dead Cow Wash
N38 44.272 W110 04.102
5.0     Keep R (L = Cut-off)
N38 44.244 W110 04.814
5.9     L up sandy slope to top of mesa
N38 44.828 W110 05.100
6.7     Keep straight (L = bailout DT)
N38 44.668 W110 05.830
6.9     Straight (R = descend to river)
N38 44.604 W110 06.042
8.1     Keep R N38 43.888 W110 06.646
8.6     L and climb up The Tubes
N38 43.486 W110 06.542
10.0   Out of wash, L on Cut-off
N38 43.537 W110 05.138
(straight = to Ten Mile)
11.0   R uphill in Dead Cow
N38 44.244 W110 04.814
11.8   Fork L (north)  N38 44.272 W110 04.102
13.9   Top of wash, fork R
15.6   Back at beginning
Getting there:
On I-70, drive about 13 miles east of Green River. Take the Floy (175) exit. Turn right (south). The pavement rapidly turns to dirt. This is the Ruby Ranch Road At mile 4.2, turn left to Blue Hills Road (note: may be impassable when muddy). Go 3.7 miles, then turn right (south) toward Ten Mile Point.  At mile 14.2, keep right to Red Wash Road. (If you're nervous about your vehicle, park here and continue on your bike. It will be three miles to Red Rim.) At mile 17.1 The Red Rim trail crosses the road N38 45.866 W110 02.345. Your ride will start by taking the Red Rim singletrack to your left south).
Water: No
Toilets: No. White Wash is a pack-out area. Remember your plastic bag and toilet paper.
Camping: Primitive, White Wash area.
Nearest bike services: Moab
From the west: If you're camping in the White Wash sand dunes area (reached via Ruby Ranch Road), you may wonder if you can bike directly to this trail. Well, yes. But even by the most rock-and-dirt intensive path, you'll push your bike through about 1/10 mile of sand as you cross White Wash. I do NOT recommend trying to drive down and through the wash. I've done it; it's not pretty.
Take Ruby Ranch Road. Keep right at mile 4.2. Stay left at mile 11. At mile 11.8, stay straight on the main road as a spur goes left to the dunes. At the next fork (just past a parking zone), go left off Ruby Ranch Road. Pass three parking zones and stop at the top of the hill overlooking the valley. Park here. Bike down the connector as it drops from the bluff after the last parking zone. When you reach sand, hoof straight across bearing straight south. You'll encounter a (still sandy-sloppy but sometimes rideable) road along the fence. When Red Wash Road turns 90 degrees left, keep going straight on the path along the fence. At mile 2.4, fork right downhill into the wash (the trail along the rim to the left is the Red Rim Trail).