Since its formation in 1917, Warren Township High School District 121 has grown and evolved with its residents. From a one-story building on O'Plaine Road to two campuses located about 4.5 miles apart, Warren has seen graduating initial classes of about 25 students in the beginning to more than 1000 today. There are more than 4,500 students divided between two campuses, representing one comprehensive high school program for more than 61,000 residents from Gurnee, Beach Park, Gages Lake, Grandwood Park, Grayslake, Millburn, Old Mill Creek, Park City, Third Lake, Wadsworth, Waukegan, Wildwood and Lake Villa.