The Wallkill Valley Rail trail runs from Gardiner, NY in the south to Rosendale in the north, covering over 12 miles of spectacular views of the Shawangunks range and running through the heart of Gardiner, New Paltz and right OVER Rosendale.
Built soon after the Civil War, the original railroad was a means for getting produce downstate to market. The eastern side of the Hudson river already had a well established rail system, but the western side, particularly in Ulster County, was lacking. The railroad connected the towns of Montgomery, Shawangunk, Gardiner, New Paltz, Kingston and Rosendale and further opened up commerce on that side of the Hudson River.
As the railroads in general began to die out, the land was purchased by a variety of groups in the hopes of creating a scenic walkway. That process began in the 1980's and the trail was formally opened in 1993.
See http://en.wikipedia.org/wiki/Wallkill_Valley_Rail_Trail and http://www.gorailtrail.org/ as well as http://www.wallkillvalleylt.org/index.php?option=com_content&task=view&id=102&Itemid=88 for more information.