Getting ThereSP member ZeeJay updated these directions from 2009
From the intersection of Highway 121 and Highway 40 in the town of Roosevelt in the Uinta Basin, drive west on 200 North (Highway 121). Stay on Highway 121 as it quickly bends to the north. Most junctions are marked with signs, but they are very hard to read in the dark. At mile 9.9, just after the actual mile marker 10 at a stop sign, at the hamlet of Neola go straight towards Uintah Canyon. At mile 16.7 continue straight. At mile 18, turn right to Uintah Canyon. At mile 21.9 turn right. At mile 22.2 turn left just after the bridge. Park at the trailhead at mile 25.6.
Mount Emmons from Lower Chain Lake
This is the easiest route to the summit of Mount Emmons. From the trailhead (7800 feet elevation), follow the trail north along the Uinta River. After about 3.6 miles, you will reach a junction. You will turn left here, crossing Sheep Bridge and onto the Chain Lakes Trail. Follow the trail, steep in places to the Chain Lakes Basin. Lower Chain Lake is about 9.2 miles from the trailhead and at 10,580 feet elevation. 4th Chain Lake is 1.8 miles beyond and at 10,900 feet elevation. Any of these lakes make a fine campsite.
There are several possibilities for climbing Mount Emmons from the Chain Lakes Basin or the Atwood Lake Basin, but I believe the route described is the easiest. Leave the trail at 4th Chain Lake and follow the stream feeding the lake into the basin before Oke Doke Lake (one of the highest lakes in Utah and is frozen well into the summer) and two ponds. Get on the east ridge of Mount Emmons, which is located to the south of the ponds where ever convenient (this is before Oke Doke Lake). Follow the ridge to the summit of Emmons. The route has 2450 feet of altitude gain over about three miles from 4th Chain Lake. The route is mostly easy with grassy and rocky slopes. Enjoy the incredible views from the summit. This peak seems to have the most far reaching views of any other peak in the Uintas, but since the summit is flat on top, you must hike to the edges of the summit plateau to see the best views.
The total distance from trailhead to summit is about 26-28 miles round trip with 5640 feet elevation gain. It is possible to climb Mount Emmons from Lake Atwood, which is the next basin beyond the Chain Lakes, but this is a longer route.
Mount Emmons from the north and Atwood Basin
A good pair of boots is needed.