Idaho Trail Ultra Series
About this race
There are now has 2 series you can join: 1: IDAHO TRAIL ULTRA SERIES (ITUS) - Finish 4 of the ultra distance events (>50K or 31 miles). For times events and backyard ultra type events finish > 50K; 2: IDAHO TRAIL SERIES (ITS)- Finish 4 of the sub-ultra distance events (between 10 miles and 30 miles). For times events and backyard ultra type events finish between 10 and 30 miles.
You can join one or both challenges!! Finishers of both series receive a custom award (Ultra Trail Challenge = running jacket and Trail Challenge = hoodie). For each challenge there will be a point system and the top 6 females and top 6 men win a Dirty Dozen Award. You cannot combine ITUS and ITS races to get your 4 finishes. You have to complete 4 ITUS events for and ITUS finish and 4 ITS races for a ITS finish. However, you can do both independently and get both awards!!
The ITUS and ITS both have 10 races races across Idaho from various race directors that offer some of the most amazing views and challenges to test your endurance, speed, and grit.
Points System:
- You accumulate points based on the distance and finish time of each race.
-
How are ITUS points configured?
- We divide the winning time by runner time and then multiply by the applicable points for that race (e.g. 31 for 50k)
- Bonus Points: 1st place -10 points; 2nd place -5 points; 3rd place -3 points. 2nd and 3rd place points are calculated on the formula BEFORE adding the bonus points.
2026 ITUS: Click on race name to check out their websites.
January
Wilson Creek Frozen 50K: January 26
March
Pulse Endurance Runs 100M, 48HR/24HR/12HR/6HR (finish at least 31 miles in the time events). March 19-21
April
Spitfire 55K: April 18
Weiser River 50K: April 25
June
Scout Mountain Ultra Trail 100M, 50M, and 50K : June 5-6
River of no Return 108K and 55K: June 20
July
Beaverhead Endurance Runs 100K and 55K: July 11
Standhope Ultra Challenge 100M and 60K: July 24-26
September
If You're Not First You're Last (Complete at least 50k): September 12
Bogus 50/50 (50M and 50K): September 26th
2026 ITS: Click on race name to check out their websites.
January
Wilson Creek Frozen 10 mile and 20 Mile: January 26
March
Pulse Endurance Runs 48HR/24HR/12HR/6HR: March 19th-21st (finish between 10 and 30 miles): March 19-21
April
Spitfire 30K: April 18
June
Scout Mountain Ultra Trail 23M: June 7
River of no Return 32K: June 20
Dirty Dog Marathon and Half Marathon: June 14th
July
Standhope Ultra Challenge 30K: July 25
August
Outlaw Trail Ultra Half Marathon: August 8
September
If You're Not First You're Last (Finish between 10 and 30 miles): September 12
Bogus 50/50 27K: September 28th
between 10 and 30 miles): January 8, 2027
Pick your distance
Running
Ultra Challenge
Trail Challenge
Typical race-day weather
Based on 11 years of Open-Meteo archive data for this event's race dates in Boise, plus the 3 days either side.
The sun rises at 8:16 AM and sets at 5:28 PM local time (MST) in Boise on January 10, 2026 — 9h 11m of daylight.
Course
No course map published yet.
The organizer hasn't released a route for this event, and we don't publish guesses. If you're the organizer, send us a GPX file and we'll draw the profile.
Reviews
Done this event?
If you've participated in this event, share your experience with other runners
Other races near Boise
Different organizers, within 40 miles, in the next three months
SueB 5k
Idaho Running Day
WIINing Warriors Flock Walk
YMCA Halloween Freaky 5K and Monster Mile
🏃 Plan Your Next Race in Boise
Find upcoming events by distance:
- Boise 5K Races 29 races
- 10K Run Events in Boise 14 races
- Boise Half Marathons 11 races
- Marathons in Boise 6 races
- Boise Running Calendar 2026 52 races
Where this page comes from. Race details were last updated on . We re-check listings regularly and again in the week before race day.
- Entries, prices, waves and inclusions — the event's official registration page
- Temperature and humidity — Copernicus ERA5 reanalysis via Open-Meteo (CC BY 4.0)
- Elevation and terrain relief — Copernicus DEM GLO-90, ESA (CC BY 4.0)
- Comparisons and counts — Race Discovery calendar, 54 Boise events
Spotted something wrong? Tell us and we'll fix it.