Tohickon Creek was named by the Lenape some of the first inhabitants of the area. "To-Hick-Hanne" means "Deer-Bone-Creek". Ralph Stover State Park was the site of an 18th-century gristmill that was built on Tohickon Creek by the park's namesake, Ralph Stover. Remnants of the mill and mill race can still be seen near Tohickon Creek. The Stover family gave their land to the Commonwealth of Pennsylvania in 1931. The recreational facilities were built during the Great Depression by the Federal Works Progress Administration created by U.S. President Franklin D. Roosevelt to provide work for the unemployed. Author James A. Michener donated the High Rocks area to the park in 1956. Although "High Rocks State Park" is listed in the United States Geological SurveyGeographic Names Information System and the coordinates given in USGS GNIS are located here, it was never an official name according to the Pennsylvania Department of Conservation and Natural Resources or a separate park.
Recreation
High Rocks is a sheer rock face, composed of smooth red Lockatong Formation argillite interspersed with friable Brunswick Formation shale. Since slippery and crumbly rock makes climbing somewhat difficult here, High Rocks is notable mostly to local climbers. Over sixty routes have been put up here over seventeen walls, with difficulties up to 5.12c/d and V7. Most are used for trad climbing and top roping, with some bouldering and sport routes present as well. Tohickon Creek offers whitewater conditions for kayaking in the spring with the winter snow melt and several times a year when water is released from Lake Nockamixon. The creek is also a warm water fishery with smallmouth bass, sunfish, carp and catfish. The Pennsylvania Fish and Boat Commission also stocks the creek with trout. A hiking trail of passes the millrace. There is a shaded picnic area along Tohickon Creek and a scenic vista at the top of High Rocks.
According to the Trewartha climate classification system, Ralph Stover State Park has a Temperate Continental climate with hot summers, cold winters and year-around precipitation. Dcao climates are characterized by at least one month having an average mean temperature ≤, four to seven months with an average mean temperature ≥, at least one month with an average mean temperature ≥ and no significant precipitation difference between seasons. Although most summer days are slightly humid at Ralph Stover State Park, episodes of heat and high humidity can occur with heat index values >. Since 1981, the highest air temperature was on 07/22/2011, and the highest daily average mean dew point was on 08/13/2016. The average wettest month is July which corresponds with the annual peak in thunderstorm activity. Since 1981, the wettest calendar day was 6.91 inches on 08/27/2011. During the winter months, the plant hardiness zone is 6b with an average annual extreme minimum air temperature of. Since 1981, the coldest air temperature was on 01/22/1984. Episodes of extreme cold and wind can occur with wind chill values <. The average annual snowfall is between 30 and 36 inches, and the average snowiest month is February which corresponds with the peak in nor’easter activity.
