There are currently 25 high schools in Montgomery County (not counting specialty or alternative programs), but some of our schools have been around before much of anything else was. Here's more about the three oldest schools in MoCo.
Richard Montgomery High School, then known as Rockville High School, is the oldest high school in Montgomery County (established in 1892). So there's no confusion, the school known as Rockville High School today was founded in 1968. Richard Montgomery was simply known as Rockville High School until 1935 when they changed the name of the school so that it could be distinguished from Rockville Colored High School, which opened in 1927.
The second oldest high school in the county is Gaithersburg High School (established in 1904). When the school first opened it was known as "Gaithersburg School" and offered grades K-12. The school was located where Gaithersburg Elementary School is currently located. The signage on the elementary school still reads "Gaithersburg School."
The third oldest school is Sherwood High School in Sandy Spring (established in 1906). The name Sherwood comes from the farm the school was built on, which was named after Robin Hood's Sherwood Forest. The original building was replaced in 1950 and then renovated between 1989 and 1991.