Mirror Lake State Park is a 2179acre Wisconsin state park in the Wisconsin Dells region. The process of establishing the park began in 1962 and the park officially opened on August 19, 1966. It contains Mirror Lake, a narrow reservoir with steep sandstone sides up to 50ft tall. The lake has a surface area of and an average depth of 10to. Recessed out of the wind, the water of Mirror Lake is usually calm and often as glassy-smooth as a mirror, hence the name. Situated in a major tourist area, the state park has an extensive campground and other visitor amenities. Also located within the park is the Seth Peterson Cottage, a Frank Lloyd Wright-designed building available for public rental.Natural historyThe region is formed from Late Cambrian sandstone deposited 500 million years ago at the bottom of shallow inland seas. During the Wisconsin glaciation between 20,000 and 10,000 years ago a glacial lobe passed just east of the park. Dell Creek, a tributary of the Wisconsin River is believed to have been blocked by outwash sediments and diverted northeast. Over time it cut a deep, narrow ravine into the easily eroded sandstone. The steep cliffs indicate that this section of Dell Creek is much younger geologically than upstream, where the banks have eroded longer and are more gently sloping.
