A picket house at this location measured 83 feet long and 18 feet wide, with a porch on this side. Built sometime in the mid to late 1850s, it was later used as a quartermaster storehouse during 1867 to 1869, and at some point it also served as a dwelling for a family with a small child. The quartermaster issued all non-food supplies at the fort, including tools, tents, equipment, weapons, and ammunition. Picket house construction, also called jacal in Spanish, was one of the most common building types on the early Texas frontier. The Spanish introduced the practice of planting posts upright in the ground and plastering them with mud when they established missions, forts, and ranches in the 1700s, and Mexican and Anglo-American settlers later continued the tradition. Because it used local materials and unskilled labor, this method produced a cheap, quick, though crude, house for new settlements. Builders dug a shallow trench in the outline of the house, stood posts upright close together in the trench, tamped small rocks and dirt around their bases, filled spaces between the posts with sticks, rocks, and clay, and then plastered the walls with a final coat of clay or lime. Most of the first picket houses here were roofed with thatch, but this one appears to have had a shingle roof made of cypress shingles from the Frio River, and records show that most houses had wooden floors made of hand-sawed boards. Described as being in an advanced state of decay in 1868, most of the fort's picket houses fell down or were torn down by the army around 1870, when their materials were salvaged for reuse at Fort Clark. Archaeological investigations in 1981 located the building's outline and studied its construction, finding only the large limestone threshold stone visible on the surface while tracing the wall lines through small limestones, charcoal, and plaster that had filled the original setting trench.