Grundy Forest To Foster Falls
In 1873 they built an experimental furnace at Tracy City that ran so hot it wrecked itself in three days. They called it the Fiery Gizzard. The trail kept the name, and the temperament.
The Fiery Gizzard Run covers the full trail from Grundy Forest to Foster Falls, which Backpacker Magazine has ranked among the top 25 hiking trails in the country. Waterfalls, house sized boulders, two hundred year old hemlocks, and sweeping ridgeline overlooks, stitched together by steep, technical drops into the gorges and back out.
The rhythm is what gets people. Long stretches of flat, fast plateau running, then the bottom falls out. The descents are rocky, rooty, and honest, and every one of them has a climb waiting on the other side. Half marathoners traverse the trail once, Grundy to Foster Falls. Marathoners run it both directions and earn every foot of roughly 7,000 feet of gain.
Thanksgiving weekend, every year. Bring the family and bring the dog. Leashed dogs are welcome on course.
Distances
Marathon
- Foster Falls to Grundy and back
- The whole trail, twice
- Roughly 7,000 feet of gain
- Raven’s Point cutoff 1:30 PM
Half Marathon
- One full traverse, Grundy to Foster Falls
- Slightly over 13.1 on the new trail
- Every marquee feature on the route
- Check in at Foster Falls or at Grundy
13 Mile Ruck
- HardRuck division, same traverse
- 20 lb dry over 150 lb bodyweight
- 10 lb dry under 150 lb bodyweight
- Weigh in 30 minutes before start
Pricing includes fees as listed on UltraSignup and can change. Shirts are a separate purchase with an order deadline posted on UltraSignup. Race proceeds help maintain the park.
Plateau Up Top, Gorges Below
The trail runs the rim of the Cumberland Plateau between Grundy Forest and Foster Falls. Up top it is fast and runnable. Then it dives: Fruit Bowl boulders the size of houses, the Blue Hole, Sycamore Falls, Black Canyon, and the long staircase descents the CCC cut in the 1930s. What goes down climbs back out.
The marquee overlook is Raven’s Point, a spur off the main line with the whole gorge laid out below. Marathoners must reach it by 1:30 PM to continue, and everyone is off trail by 5:00 PM at Foster Falls.
Aid stations sit 6 to 8 miles apart because there are only so many places a vehicle can reach this trail. Carry your own water and nutrition between them. Stations are stocked with Spring Energy gels, water, electrolytes and snacks, and the race is cupless.
Cutoffs
This is a state park natural area with a hard cap of 175 runners. The cap is the park’s, not ours, and it is why this race stays small and stays special.
Course Records
Marathon
| 1 | Chris Carter | 4:00:38 | 2015 |
| 2 | Wilton Norris | 4:02:09 | 2022 |
| 3 | William Sickenberger | 4:05:23 | 2023 |
| 1 | Malinda Honkus | 4:58:36 | 2014 |
| 2 | Cassidy Gupton | 5:06:45 | 2018 |
| 3 | Eunice Campbell | 5:11:38 | 2014 |
Half Marathon
| 1 | Kevin Mills | 1:56:57 | 2018 |
| 2 | Hunter Hall | 1:57:47 | 2016 |
| 3 | Dan Rose | 1:59:54 | 2021 |
| 1 | Maude Ariosa | 2:27:19 | 2022 |
| 2 | Taralynn Mack | 2:27:26 | 2023 |
| 3 | Megan Scheumann | 2:28:23 | 2021 |
13 Mile Ruck
| 1 | Zac Cole | 3:13:37 | 2023 |
| 2 | Nick Smith | 3:27:39 | 2023 |
| 3 | Gregory Smith | 3:51:58 | 2023 |
| 1 | Lauren Beihoffer | 3:37:16 | 2025 |
| 2 | Shyla Hensley | 3:37:17 | 2025 |
| 3 | Jenne Callahan | 3:59:51 | 2023 |
Marathon and half records per UltraSignup’s all time lists. HardRuck records compiled from the official ruck division results, 2023 to 2025.
HardRuck Info
Thirteen miles of the Gizzard with a loaded pack. Over 150 pounds bodyweight carries 20 pounds dry. Under 150 carries 10 pounds dry. Steel plate, vest blocks, or anything with the weight clearly stamped on it.
Weigh in 30 minutes before the start. Weight stays on the whole way and random checks happen on course.
Sign Up to RuckThe Day Itself
Awards
Family at the falls, dogs on leashes, and a field small enough that the finish line knows your name. Race proceeds help maintain the park.
Questions
How hard is it really
About 3,500 feet of gain every 13 miles, most of it stacked into short, steep, technical gorge walls. The plateau miles are fast. The gorges are not. Marathoners do all of it twice.
How does the half marathon start work
Two options. Check in at Foster Falls before 8:00 AM and drive to Grundy Forest, or check in directly at Grundy at 8:30. The half and the ruck start there at 9:30 and run back to Foster Falls.
What do I carry
Your own water and calories. Aid stations sit 6 to 8 miles apart because vehicles cannot reach most of this trail. The race is cupless, and stations carry Spring Energy gels, water, electrolytes and snacks.
Can I bring my dog
Yes, on a leash, and plenty of people do.
What is the weather like
Late November on the plateau. Freezing starts are normal, the gorges hold cold air and spray, and afternoons can be pleasant. Layers, and something dry for the finish.
Is there medical on course
Basic first aid and sweepers. This is a remote trail and self sufficiency is part of the deal. Any rescue costs are the runner’s responsibility.
Why It Is Called That
Nobody knows for certain, and every version is good.
The documented one: in 1873 the Tennessee Coal and Railroad Company built an experimental blast furnace at Tracy City to test whether local coal could make iron. It ran so violently hot that men nicknamed it the Fiery Gizzard. It burned for three days, produced about fifteen tons of iron, and then its stack collapsed. The furnace failed. The name stuck to the creek, the gorge, and the trail.
The legends are more fun. One says Davy Crockett, camped in the gorge, burned his tongue on a turkey gizzard straight off the fire and spat it into the creek. Another says a Native chief threw a turkey gizzard into the flames at a peace council to command the attention of European settlers.
What is not legend: the gorge you run through holds hemlocks over two hundred years old, and the stone steps you descend near the Fruit Bowl were cut by Civilian Conservation Corps Company 1475 in the 1930s. Blue Hole, Sycamore Falls, Chimney Rock, Black Canyon, Raven’s Point. Backpacker Magazine ranks this among the Top 25 trails in the country, and on the last Saturday of November, it is your race course.
The Furnace, 1873
Three days of fire, fifteen tons of iron, one collapsed stack, and a name that outlived the whole coal industry that built it. The mines and coke ovens around Tracy City are gone. The Gizzard kept burning in the only way that lasted.
The Short Version
Old fire, old stone, old trees, cold water, and a trail that earns its reputation twice a day. You will understand the name by mile ten.
Sources: Tennessee State Parks, Backpacker Magazine, and the historical record of the Tennessee Coal and Railroad Company.
Come Join Us At The Gizz
Thanksgiving Saturday on a Top 25 trail, capped at 175 by the park. November 28, 2026. 175 spots, set by the park.
Register Now