Mission Trails Historic Sites

Wednesday, August 26, 2015

Pioneer Flour Mills

Pioneer Flour Mills was initially founded as the C.H. Guenther Mill by Carl Hilmar Guenther, a millwright who immigrated to the United States from Germany in the late 1840s. Guenther built his first mill in 1851 in Fredericksburg and later relocated it one mile south of San Antonio in 1859. Guenther’s first mill in San Antonio was located along the San Antonio River across from King William Street adjacent to his home and on the grounds of the present day Pioneer Flour Mills. Guenther’s mill was the first flour mill and the first steam and water powered mill built in the city. Soon after its construction, the mill began to serve as a meeting place for the German community within the area. Guenther’s mill proved to be so successful that he expanded his business and constructed a second mill in 1868. This mill became known as Guenther’s Upper Mill and was located upstream across from Washington and Beauregard Streets. The first mill became known as the Lower Mill (Unknown n.d.).

Both mills processed grain that was grown within the area until the arrival of the railroad in 1876, which brought better grain that was grown in the Midwest and also allowed the finished product to be shipped to more distant markets. In 1878, Guenther’s two sons Arthur and Fritz joined the company, and the name was changed to C.H. Guenther and Sons. That same year, the Lower Mill was replaced with a 3-story wooden structure that could produce a much larger amount of flour. To keep up with product demand and to stay ahead of the competition from nearby mills, Guenther began to incorporate the latest equipment. In the early 1890s, the original French-made millstones were replaced with newly developed steel rollers, and steam power replaced waterwheels.

Additionally, Guenther acquired state-of-the-art sifting equipment. At the end of the century the company's 200-horsepower engine was the largest in San Antonio. The mills produced several grades of flour indicated by different labels such as “Guenther’s Best,” “Texas Pioneer,” “White Wings,” and “La Paloma” (Unknown n.d.)

Carl Guenther died in 1902. By this time his son Erhard was president of the company, which had become known as Pioneer Flour Mills, building on the recognition of one of its top selling brands. Business continued to grow, and in 1914 the company replaced its wood-frame mill with a six-story, concrete and steel building. The increased capacity was necessary to supply the new military bases in San Antonio constructed during and after World War I. Additional buildings included the twenty-story crenellated grain elevator tower built in 1922 that currently dominates the setting at the complex, the 7-story mill built in 1924, and the storage tanks, built in 1929. The company continued to prosper, even during and after the Great Depression, largely because they began to produce convenience and pre-mixed foods such as breakfast cereal and biscuit mixes. In the 1970s the Pioneer mill began selling in the foodservice market and later acquired several smaller baking enterprises and plants outside of Texas. Pioneer Flour Mills was determined eligible for listing in the National Register of Historic Places in 2006 (Unknown n.d.; Sanborn Fire Insurance Company var.).

More information regarding the history of Pioneer Flour Mills can be found at the Texas State Historical Association’s Handbook of Texas Online at and the C.H. Guenther and Sons website.


  • Unknown

    n.d. - Pioneer Flour Mills Historic Designation Verified Certificate, Exceptional Landmark, City Ordinance #64540, Copy on file at the City of San Antonio Historic Preservation Office.

  • Sanborn Fire Insurance Maps, var.

Location ID88
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