Seneca Valley High School in Germantown remains the largest public high school in Maryland by square footage. Later in this article, we’ll take a look at some of the other Maryland high schools that come closest to Seneca Valley in size.
Located at 19401 Crystal Rock Dr., the current Seneca Valley building opened in 2021 and encompasses approximately 440,000 to 452,000 square feet, depending on the source and measurement used. While there is no comprehensive statewide database ranking Maryland high schools by total building square footage, our research continues to indicate that Seneca Valley is the largest public high school facility in the state.
The school originally opened in 1974 on property that once belonged to legendary baseball pitcher Walter Johnson, who purchased the land in 1935 and lived there with his family until his death in 1946. Before Northwest High School opened in 1998, Seneca Valley was Germantown’s only high school.
During its inaugural 1974-1975 school year, Seneca Valley, led by Principal Nathan Pearson, served students in grades seven through ten. The following year it served grades nine through eleven as eighth graders transitioned to the newly established Ridgeview Junior High School in Gaithersburg. By the 1976-1977 school year, Seneca Valley had transitioned into a senior high school serving grades ten through twelve and celebrated its first graduating class in June 1977. The school adopted its current grades nine through twelve structure in 1988.
The original Seneca Valley building was demolished in 2020 as part of the construction of the massive replacement facility, which opened to students in 2021. The new school consists of two primary sections, a four-story academic wing and a two-story public wing. Classrooms in the academic portion surround two large courtyards designed to bring natural light into the building while helping students move efficiently throughout the school.
The public wing includes a 900-seat auditorium, athletic facilities and a dining hall. Seneca Valley also features a Career and Technical Education wing with programs including automotive, construction trades, architectural design and technical drawing.
Sustainability features include a vegetated roof system, while the campus includes a multi-use turf stadium, seven tennis courts, four basketball courts and grass baseball and softball fields. The facility has also received recognition for its design and construction, including an Honorable Mention in the 2022 Excellence in Construction awards from the Associated Builders and Contractors of Metro Washington and Virginia and an Outstanding Project honor in Learning By Design’s 2022 Architectural and Interior Design Awards of Excellence.
Seneca Valley’s enormous physical footprint is particularly notable because it isn’t Maryland’s largest high school by enrollment. By 2025, the school ranked 16th in the state based on student enrollment.
There is no publicly available database listing the square footage of every Maryland high school, making it difficult to produce a definitive statewide ranking. Based on our research into individual school construction and facility records, however, several of Maryland’s other largest high school buildings remain well below Seneca Valley’s roughly 440,000-plus square feet.
Montgomery Blair High School in Silver Spring is approximately 378,000 square feet, while Severna Park High School in Anne Arundel County is approximately 354,000 to 366,000 square feet. Gaithersburg High School, which was rebuilt in 2013, is approximately 325,000-plus square feet, while Bowie’s high school facilities total approximately 330,000-plus square feet across its main and annex buildings.
Two upcoming projects will also rank among Maryland’s largest high school facilities. The future Wootton High School facility planned for the Crown Farm site in Gaithersburg is expected to be approximately 358,000 square feet, while plans for a rebuilt Towson High School have called for a facility in the approximately 320,000 to 340,000-square-foot range.
Even with those major projects on the horizon, none of the identified facilities approach the overall size of Seneca Valley, leaving the Germantown school as Maryland’s largest public high school by square footage based on available facility records and our research.
