My goal was to complete 3 out-and-backs of the Rail Trail and cover about 52 miles. I started this supported attempt at the Train Exhibit at the north end nearest the Visitor's Center at Mammoth Cave National Park (mile marker 0.25) at 7:03am on December 12th. My brother, Anthony Groft, started the run with me and completed the first 3 of 6 laps, setting the pace for a good marathon split. The southern turn around point for each lap was at the "Zion Hill Baptist Church" sign before the paved path enters Park City on the south side of the interstate in front of Dollar General. At each turn I filled water flasks from stashed water jugs and picked up a resupply of gels and bars. I completed the final 3 laps solo, with a slump in pace on the 4th lap but recovering to hit the pace goal on the final 2 laps. I finished at 2:32 pm at the north end. Watch time was 7:28:39.
The weather was favorable with highs in the 50's with no precipitation. With about 3,000ft of vertical gain over the whole effort, this route was relatively flat with the vert coming in 2 short sections with many other sections where you can pin your ears back and open the stride. During the warmer months there is a water faucet at the north end making an unsupported attempt very feasible. Heads up for overly friendly dogs, leashed and unleashed.
Course Map and Historical Description found at link below.
https://www.nps.gov/maca/planyourvisit/upload/Site-Bulletin-Mammoth-Cave-RR-Bike-Hike-Trail_Web.pdf