Marathon Independent School District is a school district based in Marathon, a census-designated place in Brewster County, Texas, United States.
Marathon ISD serves Marathon and a few surrounding areas of northeastern Brewster County. The district has one K-12 school, with two buildings: a secondary school building and an elementary school building.
It is classified as a 1A school by the UIL. Typically due to its isolation, Marathon generally has the lowest high school enrollment in the state. Marathon's secondary division serves grades 7-12. For the 2024-2025 school year, the school was given a "C" by the Texas Education Agency.
As of 2007, the Texas State Energy Conservation Office awards Marathon ISD money due to the colonias served by the district.
In 2009, the school district was rated "recognized" by the Texas Education Agency.
The Marathon Mustangs compete in the following sports -
(Both teams were undefeated).
Marathon was also undefeated in 1969 and 1970.
Other high schools in Brewster County: