Garrett County () is the westernmost county of the U.S. state of Maryland. As of the 2020 census, the population was 28,806, making it the third-least populous county in Maryland. Its county seat is Oakland. The county was named for John Work Garrett (1820–1884), president of the Baltimore and Ohio Railroad. Created from Allegany County, Maryland in 1872, it was the last Maryland county to be formed. Garrett County has long been part of the media market of Pittsburgh, Pennsylvania. It is considered to be a part of Western Maryland. The Commonwealth of Pennsylvania is to the north. The Maryland–Pennsylvania boundary is commonly known as the Mason–Dixon line. The eastern border with Allegany County was defined by the Bauer Report, submitted to Governor Lloyd Lowndes, Jr. on November 9, 1898. The Potomac River and State of West Virginia lie to the south and west. Garrett County lies in the Allegheny Mountains, which here form the western flank of the Appalachian Mountain Range. Hoye-Crest, a summit along Backbone Mountain, is the highest point in Maryland at an elevation of . The Eastern Continental Divide runs along portions of Backbone Mountain. The western part of the county, drained by the Youghiogheny River, is the only part of Maryland within the Mississippi River drainage basin. All other parts of the county are in the Chesapeake Bay basin. The National Register of Historic Places listings in Garrett County, Maryland has 20 National Register of Historic Places properties and districts, including Casselman Bridge, National Road a National Historic Landmark. Garrett County is part of Maryland's 6th congressional district. The extreme south of the county lies within the United States National Radio Quiet Zone. History In the early 20th century, the railroad and tourism started to decline. Coal mining and timber production continued at a much slower pace. Today, tourism has made a dramatic rebound in the county with logging and farming making up the greatest part of the economic base. Due to a cool climate and lack of any large city, Garrett County has remained a sparsely populated rural area. Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (1.3%) is water. It is the second-largest county in Maryland by land area. Garrett County is Maryland's westernmost, bordering Pennsylvania to the north via the Mason–Dixon line, West Virginia to the south and west (with