2017 - 2018 USA Ultramarathon Calendar in May

Browse our Ultramarathon Calendar for races organized in USA during the month of May among 120 races.

120 races

Greenland Trail 50k

Greenland Trail 50k
May 05, 2018 Race day in 10 months
USA / Mountain Region / Colorado / Larkspur
Ultramarathon - 50 kilometers
Trail Fast

Knock on Wood

Knock on Wood 100 Mile
May 18, 2018 Race day in 11 months
USA / South Atlantic / South Carolina / Greenville
Ultramarathon - 100 miles
Trail

Nirvana Ultra Big Bear

100 Miler
May 07, 2016 The race has already taken place.
USA / Pacific / California / San Bernardino National Forest
Ultramarathon - 100 miles
Trail Nirvana Racing Co. Ultra Marathons Mountain

Nirvana Ultra Big Bear

50 Miler
May 07, 2016 The race has already taken place.
USA / Pacific / California / San Bernardino National Forest
Ultramarathon - 50 miles
Trail Nirvana Racing Co. Ultra Marathons Mountain

All Day 5K

May 07, 2016 The race has already taken place.
USA / Mountain Region / Arizona / Chino Valley
Ultramarathon - 50 kilometers

Rhode Island Red Runs

Rhode Island Red 50K
May 08, 2016 The race has already taken place.
USA / New England / Rhode Island / Warwick
Ultramarathon - 50 kilometers
Trail

Rhode Island Red Runs

Rhode Island Red 50M
May 08, 2016 The race has already taken place.
USA / New England / Rhode Island / Warwick
Ultramarathon - 50 miles
Trail

Quest for the Crest 10km

50K
May 20, 2016 The race has already taken place.
USA / South Atlantic / North Carolina / Burnsville
Ultramarathon - 50 kilometers
Trail Run Bum Tours Mountain

Thunder Rock 100 Mile Trail Race

No race in 2017
USA / East South Central / Tennessee / Ducktown
Ultramarathon - 100 miles
Hilly

Gamelands Ultra

Gamelands Ultra 100K
May 21, 2016 The race has already taken place.
USA / South Atlantic / North Carolina / Wagram
Ultramarathon - 100 kilometers
Trail

Gamelands Ultra

Gamelands Ultra 50K
May 21, 2016 The race has already taken place.
USA / South Atlantic / North Carolina / Wagram
Ultramarathon - 50 kilometers
Trail

PEAK Ultra Marathon

30 Miles
May 04, 2017 The race has already taken place.
USA / New England / Vermont / Pittsfield
Ultramarathon - 30 miles
Trail