Wisconsin Governor Jim Doyle, three other governors and the US agriculture secretary say they will work together to restore an area known as the Driftless Area in the Midwest.
The 24,000-square-mile covers parts of western Wisconsin, southeastern Minnesota, eastern Iowa and the northwestern corner of Illinois.
The effort aims to conserve and restore the area marked by limestone bluffs, caves, waterfalls, springs and streams.
Besides Doyle, Rod Blagojevich of Illinois, Tom Vilsack of Iowa, Tim Pawlenty of Minnesota and Agriculture Secretary Mike Johanns signed the resolution. It was introduced Wednesday at a ceremony in La Crosse.
The area's 3,600 miles of streams are marred by decreasing water quality and shrinking fish populations.
It's sometimes called the Driftless Area because it was bypassed by the last glacier some 12,000 years ago.