Mary's Slickrock Trail
Mary's Trail is found about 20 miles southeast of Green River just east of the White Wash sand dunes. This trail is 4.6 miles in length, with about 3.5 miles of Entrada sandstone slickrock. A loop ride of the entire trail is 10 miles, a shorter-less technical version is 6 miles. This area is predominantly used by the moto crowd, who ride in from White Wash. This ride is recommended only for experts.
Riding notes, clockwise loop:
0.0   From Red Rim trail on Red Wash Road
N38 45.866 W110 02.345
North on Kids Loop East
0.6   L on No Name Mesa trail
N38 46.358 W110 02.256
0.8   R on Mary's (dirt singletrack)
N38 46.418 W110 02.361
1.2   R uphill on sandstone
N38 46.706 W110 02.128
3.2   Cross Brian's Trail N38 46.146 W110 00.763
Option: R for easier ride
3.7   Steep climb N38 46.044 W110 00.485
3.9   Steep descent N38 45.967 W110 00.327
4.0   L to stay on Mary's N38 45.948 W110 00.254
4.4   Duma Rim joins somewhere here
5.4   R on road N38 45.950 W109 58.840
6.4   Keep straight N38 45.225 W109 59.464
7.3   R on Red Wash Road N38 44.963 W110 00.147
7.4   Red Slot trail on R N38 44.949 W110 00.287
9.0   Cattleguard (Red Slot before, Brian's after)
N38 45.211 W110 01.648
10.2 Back at start
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. Go 3.7 miles, then turn right (south) toward Ten Mile Point. The Enduro Loop will cross a bit later, then will cross again. Drive past the sandy east entry to Mary's trail at mile 8.5 from the highway. At mile 14.1, you pass the entry to Red Butte. Just after that, keep right to Red Wash Road. At mile 17.1 The Red Rim trail crosses the road N38 45.866 W110 02.345. Your ride will start by forking to the right on a trail that's unsigned but becomes East Kid's Loop.
Copyright 2013 Mad Scientist Software Inc.  Conditions change. Use this trail guide at your own risk.
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. Navigate to the far south end, where the connector 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. Continue on Red Wash Road until 3.1 miles since you dropped off the bluff. The trail to your right is signed Red Rim. Go to the left toward the slickrock butte on the north.