The report, released Monday by the nonpartisan Public Policy Forum research group, said the undeveloped land includes farms, wetlands, woods, lakes and open lands in Kenosha, Milwaukee, Ozaukee, Racine, Walworth, Washington and Waukesha counties.

The report found Milwaukee County is the region's most developed county at nearly 75 percent of its land and Walworth County the least at 13 percent. In between are Washington County at 18 percent, Racine and Kenosha counties at 22 percent, Ozaukee County at 23 percent and Waukesha County at 36 percent.