Green River, which serves as Sweetwater County's seat, is a historic railroad town, split in two by the Green River itself. Rimming the valley that the town rests in are impressive rock formations. Green River has enough natural beauty within the city limits that acting as the gateway to Flaming Gorge is almost an extra. Within the bounds of the river are rainbow and brown trout, catfish and Kokanee salmon and waterfowl are common all along the banks. Three natural areas, including the Scotts Bottom and Green Belt Nature Areas, line those banks. The last natural area, Expedition Island, was were John Wesley Powell began his late-nineteenth-century river expedition down the Green and the Colorado Rivers. He would end up in the Grand Canyon.
The historic richness of Green River is preserved in the Sweetwater Historical Museum - but the historical railroad is still there. Like the Green River, the Union Pacific still runs through the town, and a railroad yard rests downtown. The downtown is well worth a visit on its own, historic as that railroad.
A little bit northeast of Green River is Rock Springs, a coal mining town of rich natural resources, famous for its strong role in energy production. A little less green than the aptly named Green River, it's similarly close to the railroad and to Flaming Gorge, a secondary gateway to the massive reservoir. It's also the gateway to the Killpecker Sand Dunes. These dunes rise over 100 feet and the field of sand stretches for over 100 miles. The rocky Leucite Hills nearby used to serve as natural corrals. Today, the dunes and hills are popular destinations for hikers and offroaders.
Both Green River and Rock Springs are along I-80. Rock Springs is about 29 miles from Flaming Gorge Reservoir, Green River about the same.