Mason Rail Road Trail The Mason Railroad Trail runs for nearly 7 miles from near the New Hampshire-Massachusetts border to Greenville, NH. This is an out-and-back trail that combines with the Greenville Recreational Trail to make a continuous journey through woodland, passing numerous creeks and a couple of ponds. Difficulty & Terrain: While the trail is generally described as easy in some sections, the full trail is considered a moderate hike that covers 17.7 mi, with an elevation gain of 715 ft. Because it was a railway, the trail is wide and mostly flat, making it a pleasant experience for walking or biking. However, hardpack with rough and bumpy sections making up 30% of total trail length means this trail isn’t great for strollers or road bikes, and there is some mud to be found at the Greenville end. Highlights: Hikers can enjoy beautiful views of Pratt Pond at the start of the journey, interesting rock cuts through massive sections of rock, and evidence of old stone walls and streams from a high vantage point. This trail is historically significant in that Henry David Thoreau rode this line on September 6, 1852, from Ayer to Mason Village before walking to Peterborough and then to the summit of Grand Monadnock. Wildlife includes Northern watersnakes and various bird species. Notable Features: This section of the Mason Rail Trail is about 90