I ran the Thunderbolt Trail today in 29:24. Because this may be a new FKT and there are very few recorded/verified attempts with precise route details, I thought it important to firmly establish the route today. I heard from a few local experts, checked a few maps, and most importantly, checked out the trail during my warmup and found a bunch of signage clearly indicating where the trail goes.
Thunderbolt Trail route details:
--The trail starts a little ways (a few 10ths of a mile?) past where Theils Rd in Adams, MA, is blocked. The remaining paved road (after the road closure) turns to dirt and meets up with a new, crushed-gravel loop that circumnavigates a pond at Greylock Glen. A few hundred meters after Theils Rd turns to dirt, there is an obvious trail junction dead ahead. Perhaps 20 feet up this trail junction, there are signs on 2 trees indicating the start of the Thunderbolt Trail. I considered the very beginning of this trail-- about 20 feet back, where it meets the dirt road-- as the beginning of Thunderbolt, and I began timing my split here.
--After perhaps 1/4 mile, the trail bears right. There is old signage on a tree. It's worth noting that the bottom half of the TBolt is blazed blue (very old paint).
--After perhaps 1/2 mile, the trail makes a quick left turn onto the Roost Trail. This turn is not marked, but after running down this left trail for 100M at the most, there is signage indicating that the TBolt continues to the right. You'll miss this whole section and end up off-trail if you're not looking for the forementioned left turn.
--Now the trail is obvious for the remainder of the ascent, which gets very, very steep. The middle portion, beginning here, seems to follow (finally) the old ski slope. Brutal.
--The TBolt joints the Appalachain Trail. Take a left and run for perhaps 1/2 mile up the AT. This section is less steep. Cross the auto road. Continue on a very short stretch of pavement/gravel to the Summit Monument/Tower, and tag it to end the segment!
-My Suunto Ambit3 Run recorded this route as 2.10 miles.
Details from my effort today:
My friends Matt Shamey and Aaron Stone hiked up via a similar route. We started at 9:15 AM from Gould Rd/Greylock Glen. I warmed up on lower trails and the first mile of the TBolt, getting lost but finding the trail, and running down this 1st mile to be sure I had the right route. I ran the trail using the route described above in 29:24, tagging the monument to finish. We spent about 30 min at the summit and then ran a nice ~8 mile route along the AT and Old Adams Rd to get back down the mountain. My mark can be improved upon, no doubt. I train for mountain races and am in competitive shape right now, but I was hampered by a very sore L calf and achilles, and I know of at least a few guys who could challenge this mark. I'll come back later this year or next spring at the latest in an effort to lower this time.
Previous FKT attempts:
A good reference: berkshirehiking.com/hikes/thunderbolt.html
-Drew Best, Amherst MA