|Castle Rock State Park|
|Location||Ogle County, Illinois, United States|
|Nearest city||Oregon, Illinois|
CASTLE ROCK STATE PARK (ILLINOIS) Latitude and Longitude:
|Area||2,000 acres (809 ha)|
|Governing body||Illinois Department of Natural Resources|
Castle Rock is a bluff of exposed St. Peter Sandstone from the Middle Ordovician period. Newly exposed sections are white quartz, while older areas have browner tints from the formation of limonite. The bluff is along the axis of the Sandwich Fault Zone, separating Ordovician exposures from those of the Cambrian period. 
Castle Rock State Park was one of eleven state parks slated to close indefinitely on November 1, 2008 due to budget cuts by former Illinois governor Rod Blagojevich.  After delay, which restored funding for some of the parks, a proposal to close seven state parks and a dozen state historic sites, including Castle Rock, went ahead on November 30, 2008.  After the impeachment of Illinois Governor Blagojevich, new governor Pat Quinn reopened the closed state parks in February.  In March 2009 Quinn announced he is committed to reopening the state historic sites by June 30, 2009. 
- Wiggers, Ray. Geology Underfoot in Illinois. pp. 39–41. Retrieved May 11, 2015.
- Dempsey, Pam G. " Governor closing 24 state sites, including Kickapoo State Park", The News Gazette ( Champaign, Illinois), August 29, 2008, accessed August 31, 2008.
- Garcia, Monique and Gregory, Ted. " State park closings a tough pill for some to swallow", Chicago Tribune, November 29, 2008, accessed April 12, 2009.
- " Governor Quinn calls on IDNR to Reopen State Parks Archived 2009-04-08 at the Wayback Machine.", ( Press release), Illinois Department of Natural Resources, February 26, 2009, accessed April 12, 2009.
- " Quinn To Reopen State Parks And Historic Sites Closed By Blagojevich", The Associated Press, via Huffington Post, March 25, 2009, accessed April 12, 2009.