This kind of rock formation is known as a hoodoo. This particular one can be found in the Paint Mines Interpretive Park located in Calhan, Colorado. This naturally eroded landscape is a nice surprise in what is otherwise a very flat part of Colorado. There are a few trails in the park, but the riverbed that runs through these rock formations is what makes the trip a memorable experience. Bring some waterproof footwear and enjoy a walk along the creek.