Tarrywile Half Marathon: Course, Elevation & Route Profile
The Tarrywile Half Marathon in Danbury's Tarrywile Park is billed by its organiser as one of the toughest trail half marathons around. One loop packs more than 900 m of climbing into many short, sometimes brutally steep ascents on technical singletrack typical of the US Northeast.
Course & Elevation
The race stays entirely inside Tarrywile Park, with start and finish off Southern Boulevard. The loop has hardly any flat ground: almost half of it climbs or descends steeply. Much of it is technical singletrack, broken by viewpoints over Danbury and the quiet lakes in the park.
The loop comes in two halves. Twice, around km 2 and km 12.5, a climb of about 125 m waits on less than a kilometre, with ramps close to 30 percent. In between come climbs of 60 to 75 m, each followed by an equally steep descent. The high point is about 130 m above the start.
The organiser, Steep Endurance, marks the course with ribbons and runs a cupless race, so you carry your own bottle. Besides the start area there is at least one aid station on course. A cash bonus is offered for a half under 1:45 for men and 2:00 for women, growing every year until someone claims it.
Pacing Strategy
On this course your watch is a poor guide. Pace swings between steep hiking and fast descents, so run by effort and plan to power-hike the two steepest climbs at km 2 and 12.5 rather than forcing them.
The biggest trap is the first steep climb after only two kilometres. Run it on start-line adrenaline and you pay on all the ramps that follow. The second half repeats the pattern of the first, and that is where the race is decided.
The steep, technical descents are where a lot of time is won, and quickly lost again to a fall. Run them with short, quick steps and look far enough ahead.
Training plan for Tarrywile Half Marathon: 12-week build
Expect two and a half to four hours, far longer than a road half. The effort is long and aerobic but punctuated by dozens of short, hard spikes on the ramps.
What matters are the two steep climbs and the sum of the descents. Train hill repeats on steep slopes, alternating running and strong hiking, and descents on technical ground so your quads can take more than 900 m of downhill.
Do your long runs on trails with roots and rocks to build sure footing when tired. Strength and stability work for calves, quads and ankles lowers the injury risk.
The organiser promises good running weather for November in Connecticut, though cool in the mornings. Also practise running with your own bottle or vest, since there are no cups.
Course Map
Profile Parameters
Slope Distribution
Climbs on Route
| Start (km) | Length | Ø Gradient | Max Gradient | Elev Gain | Category |
|---|---|---|---|---|---|
| KM 0.9 | 0.7 km | 8.6% | 17.2% | +58m | — |
| KM 2.1 | 0.8 km | 14.8% | 28.7% | +126m | Cat. 4 |
| KM 6.6 | 0.8 km | 8.6% | 13.3% | +65m | — |
| KM 8.8 | 0.8 km | 8.8% | 20.4% | +75m | — |
| KM 11.3 | 0.7 km | 8.9% | 17.1% | +58m | — |
| KM 12.5 | 0.8 km | 15.2% | 28.9% | +126m | Cat. 4 |
| KM 16.9 | 0.8 km | 8.6% | 13.3% | +65m | — |
| KM 19.1 | 0.8 km | 8.8% | 20.7% | +74m | — |
Climb categories follow the road-cycling convention and rate the terrain itself (length and gradient) regardless of sport: Cat. 4 marks the easiest rated climbs, Cat. 1 the hardest, and HC (hors catégorie, “beyond categorization”) is reserved for the most brutal ascents. Short climbs below the Cat. 4 threshold stay unrated.
Course as GPX
Download the Half Marathon course as a GPX file for your watch or bike computer.
Adaptive race preparation
Let YOUB adapt your plan for Tarrywile Half Marathon dynamically
Ben connects your goal, the course, current load, recovery, and calendar. Your plan stays pointed at race day even when real life is not perfectly plannable.
Frequently asked questions
How long is Tarrywile Half Marathon?
Tarrywile Half Marathon is 21.1 km long. That distance shapes how much aerobic endurance, pace durability, and race-specific work belong in the training plan.
How much elevation gain does Tarrywile Half Marathon have?
Tarrywile Half Marathon has around 916 m of elevation gain over 21.1 km. That affects pacing, muscular load, and preparation for late-race sections.
What is the route profile of Tarrywile Half Marathon?
Tarrywile Half Marathon is classified as Mountainous, averaging 44.3 vertical metres per kilometre. 10% of the route is flat, 26% climbs moderately (2 to 6%) and 24% is steeper than 6%.
What climbs does Tarrywile Half Marathon have?
The hardest climb of Tarrywile Half Marathon starts at kilometre 2.2, runs for 0.9 km at an average of 14.8% and gains 126 metres. Cycling-convention rating: Cat. 4. 8 climbs are mapped in total.
Is Tarrywile Half Marathon a loop course?
Yes, Tarrywile Half Marathon is laid out as a loop: start and finish are in the same place.
Is there a GPX file for the Tarrywile Half Marathon course?
Yes. The Tarrywile Half Marathon course is on this page as a free GPX download — ready to import into Garmin, Wahoo, Komoot, Strava or any other app that reads GPX.
How should I prepare for Tarrywile Half Marathon?
Preparation for Tarrywile Half Marathon should account for 21.1 km, 916 m of elevation gain, current training load, and available training time. An adaptive plan helps place key sessions without ignoring recovery and real life.
What pacing strategy works for Tarrywile Half Marathon?
The pacing strategy for Tarrywile Half Marathon should reflect 21.1 km, 916 m of elevation gain, and your current fitness. Start controlled and keep margin for sections where the profile or fatigue makes target pace harder.
When does Tarrywile Half Marathon take place?
Tarrywile Half Marathon takes place on November 15, 2026.
Where does Tarrywile Half Marathon take place?
Tarrywile Half Marathon takes place in Danbury, United States.
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