I have not only heard of a split-grade high school, I attended one in La Grange, Ill. At Lyons Two High School, the campuses where approximately two miles apart, there was bus service to both campuses, but you had to live more 1.5 miles away from the school to receive it.
The swimming pool was at the north school, along with practice track and field facilities. The baseball, football and soccer fields were at the south school. All the major extracurricular functions - dances, concerts, plays, sports rallies - were held at either school depending on the seating needed for each event.
The south campus taught freshmen and sophomores and also had a small theater stage. The north campus taught juniors and seniors and had the larger production stage. If a kid wanted to join a club or activity being held at the other campus, an after-school bus was provided, or they could walk. Students were not allowed to drive to the south campus, and parking was at a premium at the north campus; most kids walked. The freshmen and sophomore campus was closed, and did have truancy officers on patrol. The junior and senior campus was open, and they also had truancy officers.
When I started school the total enrollment was over 3,000, when I graduated my class was approximately 1,300 students. As a freshmen student I was not intimidated or tempted by the older kids. And we all looked forward to getting to north and becoming an upperclassmen and getting to take the advanced classes.
Currently, I am opposed to building a new high school, and dividing the town, but if a split campus was to be built, I would then wholeheartedly support a new high school.
Susan Le Beau