2017 - 2018 USA Ultramarathon Calendar in May

Browse our Ultramarathon Calendar for races organized in USA during the month of May among 122 races.

122 races

Greenland Trail 50k

May 05, 2018 Race day in 9 months
USA / Mountain Region / Colorado / Larkspur
Ultramarathon
Trail Fast

Ragnar Trail Kentuckiana-KY, Presented by Salomon

May 11, 2018 Race day in 9 months
USA / East South Central / Kentucky / Brandenburg
Ultramarathon
Trail

Ragnar Trail Zion- UT, Presented by Salomon

May 11, 2018 Race day in 9 months
USA / Mountain Region / Utah / Mount Carmel
Ultramarathon
Trail

Glacier Ridge Trail Ultramarathon

May 12, 2018 Race day in 9 months
USA / Mid-Atlantic / Pennsylvania / Moraine State Park
Ultramarathon
Hilly Trail Relay

Glacier Ridge Trail Ultramarathon

May 12, 2018 Race day in 9 months
USA / Mid-Atlantic / Pennsylvania / Moraine State Park
Ultramarathon
Hilly Trail

Glacier Ridge Trail Ultramarathon

May 12, 2018 Race day in 9 months
USA / Mid-Atlantic / Pennsylvania / Moraine State Park
Ultramarathon
Hilly Trail

Knock on Wood

May 18, 2018 Race day in 9 months
USA / South Atlantic / South Carolina / Greenville
Ultramarathon
Trail

Keys 100

May 19, 2018 Race day in 9 months
USA / South Atlantic / Florida / Key Largo
Ultramarathon
Charity Relay

Keys 100

May 19, 2018 Race day in 9 months
USA / South Atlantic / Florida / Key Largo
Ultramarathon

Keys 100

May 19, 2018 Race day in 9 months
USA / South Atlantic / Florida / Key Largo
Ultramarathon
Relay

All Day 5K

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

Nirvana Ultra Big Bear

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