District 155

Community High School District 155 includes four comprehensive high schools and one alternate education campus. Serving grades 9 - 12, each institution has full State of Illinois recognition and accreditation. Enrollment includes more than 7,000 students from Bull Valley, Burton's Bridge, Cary, Crystal Lake, Fox River Grove, Lake in the Hills, Lakewood, Oakwood Hills, Prairie Grove, and Ridgefield. The district covers 67.75 square miles located approximately 45 miles northwest of Chicago in McHenry County. 

Beginning in 1883, a single public school, Union School, taught all Crystal Lake elementary and high school students. in 1906, Crystal Lake High School was split from Union School, and 18 years later moved to the current building that house Crystal Lake Central. In 1936, Community High School District 155 began serving Crystal Lake, Cary, and Fox River Grove. All high school students attended Crystal Lake Community High School until 1961, when Cary-Grove High School was opened. Crystal Lake South High School opened in 1978. At that time, Crystal Lake Community High School became Crystal Lake Central. A fourth high school, Prairie Ridge, was opened in 1997. The district opened an alternative education campus, Haber Oaks Campus, in 2008.

Students come to the high schools from several public school feeder districts including Crystal Lake District 47, Cary Community Consolidated School District 26, Fox River Grove School District 3, and Prairie Grove School District 46.

All District 155 juniors take the American College Test (ACT) as part of the Prairie State Achievement Exam. The composite score for Community High School District 155 seniors graduating in 2011 is 22.9 compared to a state average of 20.9 and a national average of 21.1. In other testing, the district’s students took 1355 AP exams in 2011 in subjects including biology, calculus, chemistry, computer science, English language & composition, physics, music theory, U.S. history, and statistics. Honor scores (three or higher) were received on 85% of these examinations. Further, 90.3% of the students in the class of 2011 continued their education beyond high school at 2- or 4-year colleges/universities or technical/vocational schools.

Each year the Chicago Sun-Times ranks some 638 high schools across Illinois. For the current year, all four District 155 schools are in the top 21% of public high schools. This includes Cary-Grove (40th, 93.7%), Prairie Ridge (53rd, top 91.7%), Crystal Lake Central (108th, 83.1%), and Crystal Lake South (133rd, 79.2%).

The district employs nearly 700 people including approximately 400 teachers, sixteen building administrators, and a full complement of district administrators, guidance counselors, social workers, school psychologists, school nurses, support staff, and special education services personnel. In the core subjects, all of the district's teachers are teaching in their academic major. In fact, 84.7% hold master's degrees or higher.

District 155 is one of Illinois' most financially healthy school districts, having received the highest financial rating from the Illinois State Board of Education for each of the last eight school years. Less than 16% of Illinois public school districts received the Financial Recognition rating, which is based on fund balance to revenue ratio, expenditures to revenue ratio, days cash on hand, short-term borrowing, and long-term debt.

Dr. Jill Hawk is the district's tenth superintendent, succeeding Mike Mills in 2005.