Blue Valley is part of the Fremont River drainage extending form just east of the Caineville Reef to Hanksville, Utah

Hanksville, Utah

Hanksville is a small town in Wayne County, Utah, United States, at the junction of State Routes 24 and 95. The town is just south of the confluence of the Fremont River and Muddy Creek, which together form the Dirty Devil River, which then flows southeast to the Colorado River...

. This stretch of the Fremont River is located approximately 15 miles east of Capitol Reef National Park

Capitol Reef National Park

Capitol Reef National Park is a United States National Park, in south-central Utah. It is 100 miles long but fairly narrow. The park, established in 1971, preserves 378 mi² and is open all year, although May through September are the most popular months.Called "Wayne Wonderland" in the 1920s...

. It is called Blue Valley because of the blue color of the Mancos Shale

Mancos Shale

The Mancos Shale or Mancos Group is an Upper Cretaceous geologic formation of the Western United States dominated by mudrock that accumulated in offshore and marine environments of the Cretaceous North American Inland Sea. The Mancos was deposited during the Cenomanian through Campanian ages,...

 that is the dominant geological formation of the Fremont river valley at that elevation. Blue Valley is the location of several ghost towns including Caineville, Giles

Giles, Utah

-External links:* at Ghost Towns of Utah...

, and Elephant. First settled by Americans (Mormon pioneers) during the late 1880s as farming and ranching communities, the settlements were all abandoned in 1910 due to flooding of the Fremont River which washed away many farms, destroyed the irrigation systems, and lowered the elevation of the river.