Run Across CT
Thompson, United States • 3 Apr 2027
Run Across CT 123
Run Across CT 123 is a point-to-point ultramarathon covering 123.2 miles across Connecticut from East Thompson to Southport. The route passes through about 25 towns and mixes maintained trails with paved backroads and local highways, with roughly 57 miles on trails. Total elevation change is moderate, with about 3,842 ft of ascent and 4,455 ft of descent.
Distance options:
- Solo 200k
- 6-person 200k relay
- 3-person 200k relay
- Solo 100k
The event uses a 36-hour overall cutoff and includes multiple aid stations staffed by volunteers. Aid stations provide hydration, electrolyte drinks, and light snacks; medical staff are available for common ultramarathon issues such as blisters and fatigue. There are five intermediate cutoffs plus a final cutoff at the finish; cutoffs are posted at specific mileages along the course to support participant and volunteer safety.
The finish is at the Boys & Girls Club in Southport. Finishers of the 200K receive a belt buckle; finishers of the 100K and relay options receive a medal. All participants receive a 2025 CT123 t-shirt and additional event swag. Registration opens on November 2, 2026. Volunteers support aid stations, course marking, checkpoints, and start/finish logistics; shifts typically range from 1.5 to 3 hours and include race swag and food. Visit the organization's website for the most recent information.