thriving independent businesses can be found in convenient areas throughout the city where access for their customers is more centralized and parking is more abundant. The south side of the city features several gravel quarries. A majority of these quarries are already exhausted, and have been allowed to fill with water, forming an area known as the Vulcan Lakes, also stretching into Lake in the Hills and Algonquin. The two northernmost lakes are now known as Three Oaks Recreation Area. Recreational operations at this site started in Autumn, 2010, and it has since become one of the most popular destinations in Crystal Lake. Education The city of Crystal Lake high schools are in a different school district than the middle schools and elementary schools. High schools in the city are run by Community High School District 155, which runs four high schools, including all three in the city of Crystal Lake. Crystal Lake Community Consolidated School District 47 runs all middle schools and elementary schools in the city of Crystal Lake. Prairie Grove Consolidated School District #46 also serves a portion of northeast Crystal Lake. There are five high schools which serve the city of Crystal Lake. The oldest, Crystal Lake Central High School (Central for short), graduated its first class in 1924 and was known as Crystal Lake Community High School when it opened. It is located in the downtown area of the city, and has an enrollment of approximately 1600. This school serves Crystal Lake and Lakewood, as well as the far west side of Huntley and southwestern Woodstock. In response to pressures from increasing population, Crystal Lake South High School (South for short), was opened in 1978. When it was completed, the school was ridiculed for being remotely located and surrounded by corn fields. It now stands boxed in by suburban development. Prairie Ridge High School (often simply called PR) opened in the fall of 1997, again due to increasing population pressure. The school stands on a hill off to the north of the city. The school serves mostly students who live in the 60012 and northern/eastern 60014 ZIP code areas of Crystal Lake, as well as Prairie Grove, Ridgefield, Oakwood Hills, and Burtons Bridge. They also serve some students who live in Cary, Woodstock, McHenry and Bull Valley. A very small portion of far-eastern Crystal Lake is served by Cary-Grove High School, which opened in 1961.