In August 2004, a major habitat reconstruction project involving stream rehabilitation and conversion of corn fields and grassy old field areas to tallgrass prairie occurred along Waterloo Creek in NE Iowa. Prior to the reconstruction, we sampled ground beetle assemblages with pitfall traps and butterflies with a visual survey along a 1 km transect to provide baseline data beginning in 2003. So far, only 13 species of butterflies and 29 species of ground beetles have been found on site. It is expected that as the more diverse tallgrass prairie habitat becomes established, both butterfly and ground beetle diversity will also increase.