The Chinook area is a large, fairly contiguous grassland created from the reclamation of earlier surface coal mining activities. The Midwest Coal Company currently controls Chinook Mine, although much of the northern end of the mine (930 ha) is now owned and managed by the Indiana Department of Natural Resources as a fish and wildlife area.
Currently, about 61% of the mine is in undisturbed grassland, with 18% in hayfields; the remaining 21% is split about evenly among wetlands, row crops, and forest. Several studies conducted by Steven Lima, Peter Scott, and other colleagues at Indiana State University, Department of Ecology, have suggested that this reclaimed grassland provides productive breeding habitats for prairie birds and, secondarily, species typical of savanna and brushland habitats.
The present method of surface-coal mine reclamation has produced a large grassland at Chinook Mine and the state-owned fish and wildlife area. The area supports large numbers of many species of obligate and facultative grassland birds, most noteably a breeding population of Henslow's Sparrows which probably exceeds 300 individuals (given a corrected point count density of 0.164 males per hectare calculated in 1997 and 0.159 in 1998). Other common species that inhabit Chinook (in descending order of abundance followed by their respective population density) include Eastern Meadowlark (58.8 birds/100 ha), Grasshopper Sparrow (37.8), Dickcissel (21.6), Common Yellowthroat (12.7), Field Sparrow (7.6), Horned Lark (4.5), and Northern Bobwhite (4.1) (see DeVault et al.). Despite the fact that most of the vegetation at Chinook is composed of non-native cool-season grasses, a two-year study conducted by Steven Lima and Edward Galligan concluded that the nesting success of such birds in reclaimed coal mines is comparable (overall) to that observed in non-mine grasslands, including native prairie fragments. The site also supports relatively large populations of raptors during the winter months, which includes such species as Northern Harrier, Rough-legged Hawk, and Short-eared Owl.
The former coal mine land near the Vigo/Clay line is considered an ideal location for a future industrial park by developers, so county officials are currently studying the feasibility of placing a new highway interchange near the southern boundary of this site. A new interchange would make the unprotected portions of Chinook readily accessible for commercial development and interstate commerce. Also, with the exception of the state's fish and wildlife area, much of the land is privately owned, and the possibility of agricultural intesification, such as increased haying and grazing within the grasslands, is always present. Such practices could produce severe negative impacts on breeding grassland birds like Henslow's Sparrow and Dickcissel (both part of Audubon's WatchList) and an overall decline in nest productivity.