In the spring of 1873, "Pie" Allen broke ground for his Post Trader's Store just as the troops arrived at the Rillito to begin work on their new camp. The original store had nineteen rooms including storerooms, a bar, gaming rooms and living quarters. By July, when the soldiers were still living in canvas tents, he was ready to open his doors to the hot and thirsty men. The store's reputation was well established by the end of that month. Allen was advised that his store would be closed if the undue amount of drunkenness continued among the enlisted men at the camp. Allen sold his store the following year to Frederick Austin who, along with his family, ran it until the last years of the Fort's occupation.
In the early 1900s the old store was first used as a tuberculosis sanitorium and later as a hog farm.
The same Bolsius family that transformed the comisario purchased the store ruins in 1934. With the help of El Fuerte neighbors, they restored the home in eight years.