Cadillac Doubleback: An unknown poster set the route:
Easy one to beat! "Cadillac Doubleback" Acadia NP cadillac entrance on 233 to kebo mtn trail to north ridge trail to cadillac summit to south ridge trail to route 3 and back. approx 3000' elevation gain. approx 12 mi (I have an old garmin 305, doesn't measure distance with elevation well). Did today with icy conditions on north ridge in 2hrs 37mins.
There are two main trails that partly overlap in the Middlesex Fells (https://www.mass.gov/locations/middlesex-fells-reservation).
This is the Reservoir Trail a 6 mile challenge.
Ben Thompson appears to have the FKT, 39 m 39 s, April 2016.
The Wapack Trail in southern NH is maintained by Friends of the Wapack Trail. There is an out & back race on this 21.4-mile trail, and the race website has information on FKTs (splits in the race). Overall 21.5 (one way) & 43.0 (out & back) mile course records are here: http://ultrasignup.com/results_event.aspx?did=19292
The [24-mile] Mohawk trail is a blue-blazed loop starting and ending on the Appalachian Trail in Northwestern Connecticut. Its southern beginning is in Cornwall Bridge and it winds through Cornwall to its northern terminus in Falls Village. Along the way are stunning views, quiet ponds, old country roads, and plenty of exercise.
The Mohawk Trail was originally part of the Appalachian Trail before the AT was rerouted east of the Housatonic River in the 1970s.
Originally the route was from Rattle River Trail Head as also seen from the early FKTs. Now the trail goes from Gorham and the Carter Moriah TH at Bangor St.
The Dartmouth Outing Club describes the route:
The Carter Traverse is a strenuous 20-mile hike over the Carter-Moriah and Wildcat ranges of the White Mountains, on the east side of Pinkham Notch. It covers six 4,000-foot summits and, despite having no above-tree line areas, provides outstanding views of the Presidentials.
Ben Nephew posted the route:
Jason Beaupre posted the challenge of hiking all 67 New England peaks over 4000':
The Paugussett Trail is a Blue-Blazed hiking trail "system" in the lower Housatonic River valley in Fairfield County and, today, is entirely in Shelton and Monroe, Connecticut. Much of the trail is in Indian Well State Park and the Town of Monroe's Webb Mountain Park. The mainline (official "Blue-Blazed") trail is primarily southeast to northwest with three short side or spur trails.
Northern Terminus: East Village Road (41.3570510, -73.1896970)
Southern Terminus: Buddington Road (41.2890360, -73.1206940)