Decent dump station. Free. Big rig friendly. Fresh water. Great Verizon LTE.

When you're leaving or heading to Flaming Gorge, or driving by on I-80, the city of Green River provides a free dump station at its water treatment plant, complete with a nearby potable water fill. It's located on the south side of town, near the town horse stables and rodeo grounds. There is a ton of space for even the biggest rigs to get into position and turn around, and it's set up for two rigs simultaneously. You pass the separate potable water fill on the way into the dump station, and I've uploaded a couple of photos of that as well, as it's not incredibly obvious.