The McElroy-Severn House, Stagecoach House, and Onion Creek Post Office stand on a 51-acre tract on a high bluff above a branch leading into Onion Creek, about a quarter mile east of Buda. Beginning in 1875, the post office and stagecoach served local residents and travelers on the Old San Antonio Road. After mail service moved to the new railroad town of DuPre, or Buda, in 1880, the former station house became a private residence and served as headquarters for a family ranching operation for more than a century. The McElroy-Severn House is a late-19th century modified center-passage dwelling, a five-bay, side-gabled frame house with a hipped-roof porch stretching across the full south facade, limestone chimneys plastered with concrete, and interior walls framed with cedar. Major remodeling campaigns in 1885, 1900, and 1920 substantially enlarged the house. The adjacent 1876 one-room post office is notable for fine craftsmanship, solid limestone construction, and carved stone lintels, with a single door facing the rear east wing of the stagecoach house and a small single-pane window cut into its east wall. Other historic resources on the site include a brick and limestone well, a concrete trough, and concrete walkways and gardens. Together, these buildings recall Buda's beginnings as isolated homesteads scattered along Onion Creek and reflect a century of the community's agricultural heritage.