The accelerating pace of conversion of natural landscapes to human-dominated ecosystems requires us to consider new ways to explore and understand natural areas. One approach is to study soundscapes, which are the collective sounds of environments; that is, sounds generated by animals, geophysical processes such as wind and rain, and humans and their activities. We studied the dawn soundscapes of forest and grassland sites at multiple Southwest Michigan Land Conservancy preserves over the summer of 2015 to assess whether acoustic diversity varies within and between sites, and in particular, how forest and grassland soundscapes differ. From our recordings, we calculated acoustic diversity indices, which have been shown to be indicators of biodiversity of sound-producing organisms. The analysis of soundscapes provides a novel and rapid assessment tool for monitoring biodiversity in natural areas.