The formation of Rib Mountain began some 1.5 to 2 billion years ago with the violent fusion, through intense heat, of sand into mammoth chunks of quartzite. Beginning 1.5 billion years ago, the surrounding plains started eroding away.

The incredibly hard quartzite, however, resisted this erosion. Over the succeeding hundreds of millions of years what remained rose higher and higher over the surrounding area, and is now called a "monadnock" by geologists.

Rib Mountain is the fourth highest point in Wisconsin at 1,940 feet above sea level and, at more than 700 feet above the surrounding plain, is the tallest hill in Wisconsin.

For more information, see our Geology link on the "Web Links" page.

Rib Mountain is one of the oldest geologic formations on earth. Established as a state park in 1934, a recent purchase of 257 acres from 3M Corporation increased park area to approximately 1500 acres. The top of the 60-foot observation tower is about 800 feet above the surrounding terrain and offers spectacular views.

Directions: Rib Mountain State Park is located southwest of the city of Wausau. Exit US Hwy 51 at County Hwy N (Exit 188), and drive west 1/3 mile to Park Road. Turn right onto Park Road and follow it up the mountain 1.7 miles to the Park contact station.