In 2004, this trail corridor was named in honor of Rachel Carson, the mother of the modern environmental movement. When complete, the Rachel Carson Greenway Trail will be 25 miles long, connecting the Anacostia Trail System in Prince George's County to Patuxent River State Park in the north, and it will eventually connect to the Seneca Creek Greenway and the Potomac River to create a 50-mile continuous trail system in Montgomery County. Along its route are places tied to the county's agricultural heritage, mills along the Hawlings River that turned grain into flour, sawed timber, and wove wool, forest habitat for birds such as the Kentucky Warbler and Ovenbird, Holland's Corner at the old toll-road intersection to Baltimore and Olney, Woodlawn Manor and the history of African Americans and Quakers in Sandy Spring, meadows and hedgerows that support wildlife, prehistoric rock shelters used by local American Indians beginning about 1000 B.C., the ruins of the Gilmore Mica Mine, vernal pools, the Northwest Branch stream valley, Burn Mill, Rachel Carson's home along the stream valley where she wrote Silent Spring, and the Fall Line gorge where Piedmont rock gives way to Coastal Plain sediments.