The Grand Mesa

colorado national monument
colorado national monument

The Grand Mesa is just east of Grand Junction, and between the Colorado River and the Gunnison river. The Grand Mesa is huge; it stands 10,000 feet above sea level, and is 53 square miles. People that visit the Grand Mesa mostly come to ski, snowboard, and snowmobile in the winter. In the summer they fish, camp, and hike. The Grand Mesa has over 200 stream-fed lakes. The Ute Indians calls the Grand Mesa the Thigunawar. The story about how the Grand Mesa was formed is very interesting.

The Grand Mesa was formed by the Colorado and Gunnison River, and geologically the mesa is the result of a hard volcanic basalt layer on its top. This layer formed approximately 10 million years ago by basalt flows, suppressed erosion compared to the surrounding sedimentary rock layers, which suffered rapid downcutting from the action of the Colorado and the Gunnison rivers. The top layer rests on a thick sequence of Tertiary rock and sandstone known as the Green River and Wasatch Formations. These layers in turn rest on a Cretaceous layer known as the Mesa Verde Group that forms a cliff about halfway up the side of the grand mesa. The lowest layers are yellow and gray Mancos shale from the early Cretaceous age. The shale continues outward into the surrounding valleys in the vicinity of the Mesa

The Grand Mesa is covered by stream fed lakes, also winters are very cold and dry There sunshine hours are abundant even in winter and total 3200 per year or 73% possible time. The lava that formed the top of the mesa has squishy moist shale underneath it. The water from the stream can cause cracks in the clay and so landslides occur and have the sides of the mesa to slurp down. The Grand Mesa is destructive and it is the largest flat top mountain of the North American. Today the grand mesa has rock like sandstone and it’s easier to break apart than regular. The mesa is made out of shale and sandstone It’s between the Colorado River and Gunnison River.