The Great Divide Basin is where the Continental Divide splits and then becomes one again.
This simple map by the US Geological Survey shows the circle in Wyoming where the Great Divide Basin is located. I drew the red arrow.

I became interested in the Great Divide River Basin because the Wyoming part of the Oregon Trail goes through it. This is a National Park Service map of the trail.

The Continental Divide splits near South Pass in the north. It is a place that the Oregon Trail passes through. This map shows South Pass  by, Matthew Trump.

This a picture, modern day, of South Pass  by NOAA.

At the split, the basin goes southeast on the left side and east on the right side.
The Oregon Trail crossed at Bridger Pass where the Great Divide Basin ends. I could not find a picture or map of this. It is in southwest Wyoming.

The Great Divide Basin is between two river watersheds. On the west side is Green River watershed. Here is a picture of it  by, G. Thomas, English Wikipedia.

On the east side is Medicine Bow River. I couldn’t find a good map of it. Here is a picture of it  by, NOAA.

The Great Divide Basin in the south, ends at Bridger Pass. It is in southwest Wyoming. I couldn’t find a good map of it. The travelers on the Oregon Trail crossed the Continental Divide here. The trail goes north west after that and then goes into South Pass.

The Great Divide Basin includes the Red Desert. The basin is high desert. Most of the water that flows into the basin evaporates. There are shallow lakes. The water stays in Wyoming with none of it flowing out of Wyoming.
There are no mountain ranges on the west or east side of the basin. This means that the west winds, which are very strong, blow across it. The land dries out in a hurry.
This is a picture of rock formations in the basin  by, MONGO, Wikipedia Commons.

The last picture gives an idea of the ground with sage brush in the Great Divide Basin. The basin is about 3,900 miles large. This picture is of wild horses in the basin  by, Bureau of Land Management.