The Great Lakes Piping Plover (Charadrius melodus) is now restricted to a few sites on Lake Michigan and Lake Superior. Despite the plover’s endangered status, habitat critical to its survival has not been designated while both breeding and wintering areas are subject to increased development and recreation pressure. A thorough analysis of available breeding habitat is essential for the development of conservation strategies that will lead to the recovery of the species. The objectives of our study are to 1) characterize critical breeding habitat for the Great Lakes Piping Plover 2) evaluate the suitability of historic and potential breeding sites and 3) assess breeding habitat in terms of its value to biodiversity conservation. Between May and August 1994 and 1995, we visited known plover nest sites and measured physical characteristics of both the immediate nesting area and surrounding habitat. In 1995 we used airborne videography to collect imagery of nesting sites for remote habitat assessment and worked with a team of biologists to gather data on rare species distributions. Immediate nesting sites contianed signficiantly more rock cover and were farther from forest than the surrounding beach. In the three counties in Michigan’s lower peninsula with the most nesting records, 6.72 miles or 6% of mainland shoreline met the minimum physical nesting requirements for Piping Plovers. Our results indicate that nesting habitat is more limiting than previously thought and that it is imperative to identify and protect quality examples of shoreline habitat for plovers and other rare organisms.