Located on the Prairie Trail Scenic Byway northwest of Marquette about 5 miles north of Kanopolis Reservoir and State Park, 3 miles west of K-141 on Avenue K, a county road or south of K-140 from Caneiro on 25th Road

One of the 8 Wonders of Kansas Geography, Mushroom Rock is the smallest, but one of the most unique, state parks in Kansas. The park is only 5 acres but boasts some of the most unusual rock formations anywhere. The rocks served as meeting places and landmarks for Native Americans and early pioneers such as John C. Fremont and Kit Carson.

Resembling giant mushrooms rising above the horizon, the Dakota formations of Mushroom Rock State Park are the remains of beach sands and sediments of the Cretaceous Period, the interval of geologic time from about 144 to 66 million years ago. Sandstone and sedimentary rock is held together by natural cement. The concretions that make up Mushroom Rocks are cemented calcium carbonate. The largest rock measures 27 feet in diameter.

About six miles to the west, in the city of Kanopolis, are four remaining buildings of Fort Harker, an active U.S. Army outpost from November 1866 to October 1872.