Lake Mary HS was the fourth high school in Seminole County, opening for the 1981-1982 academic year. The 300,000-square-foot physical plant included an 800 seat Auditorium, 890 seat Cafeteria, 2,200 seat Gymnasium,
Media Center, and 13 computer labs. The high school grounds contain a 4,500 seat stadium, lighted baseball field, softball field, track, tennis and handball courts, and an indoor practice building. Since 2002, the campus has undergone a $20 million project involving both new construction and remodeling, funded by a county-wide sales tax.
A new 27,000-square-foot Auditorium with modern band, chorus, dance and drama facilities opened in July 2003, along with a 6,000 sq. ft. Multipurpose Fieldhouse. The main building remodeling includes a new Media Center (14,500 sq. ft.), CCTV studios, additional classrooms, relocation of Administration, and expanded Applied Technology labs. The final phase completed in 2006 provided practice fields and courts, parking and drainage improvements,
In May 2008, the new auditorium was named for Alice Ann Nilsen (retired choral director-23 years) and Terry Pattishall (retired band director-27 years).
The band under the direction of Ms.Terry Pattishall received national acclaim throughout her tenure as director. In 1984, LMHS Band was selected to perform in the Macy's Thanksgiving Day Parade and Ms. Pattishall was the first female high school band director to bring a band to Macy's. The Marching Band has also performed at the Sugar Bowl (1989), the Cherry Blossom Parade in Washington, D.C. (1993), and the Thanksgiving Day Parade in Chicago (1996). In 2001, the Marching Band played in Regency Park, London, under the Eiffel Tower in Paris, and in 2009 marched in the London New Year's Day Parade.
The total program under Ms. Pattishall's leadership received 27 consecutive years of STRAIGHT SUPERIOR ratings at Marching, District and State Concert Festivals. LMHS also boasts hundreds of students performing in All State, All County and honor groups throughout the state.