Gravel chub silt and debris. They are more often found in areas with limited macrophytes and larger root aquatic plants, algae and moss. Because of their need of a specialized clean habitats, the gravel chub is especially vulnerable to various forms of pollution, especially from agriculture practices that create erosion and excessive silt. In past sampling surveys the gravel chub had been found as far north in the Upper Iowa River as Le Roy, Minnesota, but because of excessive amounts of sewage, pesticides and sedimentation of rocks and sand, this is no longer the case. The presence of gravel chubs in a
Dravo Gravel Site Dravo. The inhabitants' technology prompted their classification as a people of the middle of the Late Archaic Period. In 1978, the Dravo site was listed on the National Register of Historic Places, qualifying because of its archaeological significance. Dravo Gravel Site The Dravo Gravel Site (33HA377) is an archaeological site located above the Great Miami River in Miami Township, Hamilton County, Ohio, United States. Discovered in the middle of a gravel pit, the site is a leading example of the local manifestation of the Archaic period. The site lies atop a Miami River terrace outside the village of Cleves, occupying