Abstract The exposure described in this report is located in Hueston Woods State Park, in Butler County, southwestern Ohio. It is southwest of Eaton, which is 7 mi (12 km) south of Interstate 70 on U.S. 127, and it is 25 mi (40 km) north of Cincinnati and 1–71 and I–75 (Fig. 1). The site (Doty’s Highbank) is located onthe east side of Four Mile Creek, 3 mi (5 km) north of Oxford (Oxford 7½-minute Quadrangle). Access to the site is by Ohio 732 (Fig.2). Turn weston Park Road and continue for about 0.5 mi (0.8 km) to a junction, turn left (south), and follow this road until it crosses Four Mile Creek. Park southwest of the bridge, walk across the bridge, and follow the east side of the creek downstream 750 ft (230 m) to a high stream-cut exposure.

Abstract This article is aimed at providing an overview of the geology of the Dayton region to those who seek an introduction to Dayton’s geological story. The oldest rocks exposed in the area are Ordovician (Katian Stage, Cincinnatian Series in local North American usage) in age, and are world famous for the quantity and quality of their fossils. Unconformably overlying the Ordovician strata are Silurian (Llandovery–Wenlock Series) dolomites, limestones, and shales, which represent tropical seas that were at times rich in crinoids, corals, brachiopods, and other invertebrates. A large time gap (unconformity) in the rock record of some 420+ million years occurs between the Silurian and the Pleistocene “Ice Age” deposits of the area. Significant changes to the natural environment in the Dayton area have occurred during the Anthropocene. A number of localities that can be reached within about 30–40 minutes from downtown Dayton are described. This is effectively Montgomery County and adjacent counties. As such this treatment is brief and not meant as a compendium but as an introduction and outline of Dayton’s geology and geological history. The localities selected illustrate Dayton’s geological heritage, from the Ordovician to the Pleistocene, while several of the area’s distinctive natural landmarks are discussed. A number of the landforms are expressions of the Niagara Escarpment, where resistant Silurian limestones and dolomites overlie less resistant older rocks.

ABSTRACT Streams in the Midwest of the United States have experienced major changes in their watersheds since European settlement that have altered sediment loads, runoff, nutrient concentrations, and the abundance of woody debris. Moreover, the near extirpation of keystone species such as beaver, and the construction of dams and impoundments (e.g., milldams, causeways, reservoirs, small ponds, etc.), have had impacts on the entrainment of sediments, the connectivity between tributaries, main channels, and floodplains, and channel form. As stream restoration efforts increase, how do we restore streams to their ‘natural’ state? Can streams restored to a pre–European settlement condition maintain equilibrium under current land use? Here we examine the impact of post-European settlement changes to a small (432 km 2 ) watershed in southwestern Ohio that is largely representative of rural watersheds in the Midwest. We examine the impact of nineteenth-century milldams, report the results of a 21-year study of nutrient and sediment concentrations in the upper portion of the watershed during a shift from conventional to conservation tillage, and assess the potential impact of the return of beavers on stream sediment and nutrient concentrations. Our objective is to understand how streams have been impacted by humans over the past 250 years, and to identify strategies for ‘restoring’ streams in the Midwest.