Western Slope

Of course it becomes drier going west.
I am heading to Dinosaur National Monument through northern Colorado to Utah. Mesas, riparian rivers, exposed rock formations, erosion, and a lot of sagebrush. This is in the east unit of Dinosaur NM.

150 million years ago, dinosaurs roamed here. Their fossils are still embedded in the rocks. Today, mountains, desert, and rivers flowing in canyons support a variety of life. Petroglyphs reveal the lives and connections of Indigenous people to this land. Homesteaders and outlaws found refuge here.
https://www.nps.gov/dino/index.htm

Paleontologist Earl Douglass of the Carnegie Museum unearthed bones from an area that turned out to be an incredible repository of ancient reptile skeletons, on August 17, 1909. It was declared a national monument in 1915.