When R.S. Sweetman purchased C.A. Wagner Construction Co. in 1952, the company specialized in heavy/highway construction. Later, Sweetman Construction Co. diversified into other phases of road building and heavy construction projects in South Dakota and surrounding states.

Founded in 1930, Concrete Materials produced crushed rock from a small processing plant in west Sioux Falls. The company later added a small sand production plant near Rowene and, after World War II, opened Sioux Falls' first ready mix concrete plant adjacent to the original rock quarry. Sweetman Construction Co. purchased Concrete Materials in 1952.

Since its inception in the 1950s, the company has continued growing and expanding. Concrete Materials owns and operates aggregate and concrete production facilities in Chancellor, Yankton, and Sioux Falls, where we also have a stone quarry, sand and gravel processing plants, ready mix concrete plants, and asphalt plants. In 1992, Concrete Materials purchased Brandon Materials Co., operating a ready mix concrete plant and a sand and gravel processing plant in nearby Brandon, SD. Ellis & Eastern Railroad Co., founded in 1987, also operates in the Sioux Falls market area. Concrete Materials expanded into the masonry block production business with the acquisition of the Gage Brothers block plant in Harrisburg, SD, and another plant in Rock Valley, IA, in the early 2000s, as well as adding various landscape block lines to their product list.

Concrete Materials is committed to producing only the very best quality materials to serve the construction industry in eastern South Dakota and surrounding states.