This walking tour will consider local geology, touch on local history, and focus on the building stones used in downtown Dayton. Building stones and construction materials used along Main Street are the main interest. Special attention will be paid to “Dayton’s own,” the Dayton limestone—a stone considered by State Geologist Edward Orton in the second half of the nineteenth century (Orton, 1870, 1893) as one of Ohio’s finest building stones. The Dayton Formation (Dayton limestone) was used extensively as a building stone in the Dayton area (and farther afield) during the nineteenth and early years of the twentieth centuries during the growth of Dayton. Perhaps the zenith of the Dayton limestone building-stone industry is characterized by the Old Courthouse (1850), an important building in the Greek-Revival architectural-style that saw the use of Dayton limestone not only for the exterior of the building but also, unusually, and perhaps with a little too much enthusiasm, for slabs of limestone for the roof. This building has much local historical significance— both Presidents Abraham Lincoln and John F. Kennedy addressed the public from its steps. Dayton limestone was used for the commemorative stone from the State of Ohio, installed in 1850, inside the Washington Memorial, Washington, D.C., and for part of the “Ohio House” built for the International Exhibition at Fairmount Park, Philadelphia, Pennsylvania, commemorating the centennial of the signing of the Declaration of Independence in 1876. Use of the stone is also documented in Cincinnati, Columbus, and Chicago.

Recent developments along East Monument Avenue and Patterson Boulevard— RiverScape and the Patterson Boulevard canal walk—as well as some of the buildings, will be discussed.

The “Great Dayton Flood” of 1913 probably resulted in excess of four hundred deaths along the Great Miami River valley and its watershed. The Miami Conservancy District oversees the flood-prevention scheme that developed after the 1913 flood; their headquarters are housed in a building that overlooks the Great Miami River in downtown Dayton. Flood-prevention modifications to the Great Miami River can be seen adjacent to downtown.