Route: Adirondack 46 High Peaks (NY)
The High Peaks is the name for the 46 highest summits in the Adirondacks of New York. Most are over 4,000 feet. Wikipedia has a nice description.
Climbing all 46 peaks over some time period has been a thing to do for decades. The ADK46-R Club has recorded thousands of people who have completed them all.
"Cave Dog" Ted Keizer set the speed record for climbing all 46 peaks June 24-27, 2002, 3d18h14m.
The record stood for 6 years, until it was broken by exactly 1 hour during June 24-27, 2008, by Jan Wellford, 3d17h14m. Jan's detailed splits for the trip are here. In an interview, Jan makes some interesting comments about the issue of style in the ADK46. In particular, Jan started his timing at the first trail head, rather than as the base of the first mountain as Cave Dog had done (adding roughly an hour to the time), and he originally intended to avoid private land and access roads, though ended up using some private access.
Because I was behind schedule so early on day 2 I was forced to hike some extra miles in order to make the route work. For example, it is easy to bushwhack from Dial to the Dix trail, but I wasn’t on Dial until after 9 pm, so the bushwhack would have been in the dark and the Dix Range would have been very difficult because of the late hour. I hiked about 153 miles—I initially thought I could do the entire route without private land in as little as 145 if I did it properly. -- Jan Wellford
As is always the case in mountaineering, "rules" and "style" are key questions for each climber.
Jan Wellford & Cory Delavalle have the FKT for an unsupported thru-hike of the 46 peaks, 7d14h15m starting September 7, 2009. Their route came to 196 miles with about 65,000 feet of elevation gain. The pair carried all their supplies and food, taking only water from natural sources. Delavalle's (very detailed!) report indicates that the 46 peaks had been done as a thru-hike with some resupply drops in 10+d in 2002 by Ed Bunk and Jim Kobak.