Photo: Courtesy of RockResorts
How you can volunteer: During the warmer months at U.S. locations, team up with U.S. Forest Service staffers and other agencies to clear local trails. A trailblazing session will save you up to 30 percent off one night's stay. In St. Lucia, help local farmers build fences and maintain gardens.
What you'll spend: Summer rates start at $139 ( RockResorts.com )
Find the volunteer vacation that's right for you