Located in southern Big Horn County, the highway serves the town of Manderson and the community (CDP) of Hyattville.

Wyoming Highway 31 is an east–west highway that starts in the town of Manderson at US 16/US 20/WYO 789 and heads north through Manderson as Sherman and Marshall Streets,[1] but turns east as it leaves the town to head toward Hyattville.

In addition Medicine Lodge State Archaeological Site [1] in Hyattville can also be reached by using Highway 31.

[citation needed] Nearing its end, WYO 31 turns south and enters the community of Hyattville and passes through the community as Main Street.

[1] The Highway 31 designation ends south of Hyattville.