Behind the Rocks Ultra
Apr 3, 2027Moab, UT50 mi, 50K +2
Also 50 miles, 2 weeks before Loud Thunder 50, registration open
Aid stations, cutoffs and pacing in one plan, with the timeline your crew follows. Crew invites and race-day updates come with a Race Pass.
Build my planWelcome to the Loud Thunder 50 presented by Sun Trail Running!
Please join us Saturday, April 18th 2026 for 50mi, 50k and 1/2 marathon trail races on the rugged, beautiful and challenging trails at Loud Thunder Forest Preserve along the mighty Mississipppi River.
Our hope is to showcase this amazing park all while providing a low key trail race experience for those looking for a challenging but rewarding late spring ultra. Our commitment is to provide the highest value event possible by keeping the cost low and the focus on the runner, the trails and this great outdoor community. Your registration fee covers all the race basics as well as custom swag, fully stocked aid stations, custom finisher awards, post-race food and drink and a guaranteed donation back to the park to help ensure future maintenance and conservation efforts.
Camping is available right at the start/finish (Horse Corral Campground) and throughout the park at a number of campgrounds. One of those campgrounds is located along the course right near the primary on-course aid station (Riverview). Reservations can be made beginning March 1st through the park at: Loud Thunder Forest Preserve Camping.
There is a 2 night minimum for online reservations. Unreserved campsites are available on a first come first serve basis with only a 1 night minimum. If you decide to camp during the race, please review and abide by all park rules and policies.
WHEN & WHERE
The 50mi starts at 6am, the 50k at 8am and the half marathon at 9am with an 8pm final cutoff for all race distances. 14hrs (50mi), 12hrs (50k), 11hrs (half marathon).
The start/finish is located at the Horse Corral Campground. Google Maps: https://goo.gl/maps/hDMQDMD5qiJd5GTEA
Park address in Google: 19408 Loud Thunder Rd, Illinois City, IL 61259
Coordinates will get you directly to the start/finish: 41.421726, -90.834335
Coming in from either the east or west on Loud Thunder Road, turn south off of Loud Thunder road and continue south on the park road following signs for the Horse Corral Campground.
Race day
Apr 17, 2027
Registration openings and major changes, like a new date or a cancellation.
Can't race, or need an entry? Post it here so nobody has to ask if it's still available.
Apr 3, 2027Moab, UT50 mi, 50K +2
Also 50 miles, 2 weeks before Loud Thunder 50, registration open
Apr 10, 2027Borden, IN50 mi
Also 50 miles, 1 week before Loud Thunder 50, registration open
May 1, 2027Mouth of Wilson, VA50 mi, 50K
Also 50 miles, 2 weeks after Loud Thunder 50, registration open
Straight-line distance
Oct 10Lake County, IL50 mi, 50K +2
Oct 10East Peoria, IL100 mi, 50 mi +3
Nov 14Pekin, IL50 mi, 30 mi +2
Nov 14Vienna, IL100 mi, 100K +2
Apr 24, 2027Palatine, IL50 mi, 50K +2
Jul 9, 2027Chillicothe, IL100 mi, 50 mi +3
Mar 27, 2027Long Grove, IA24 hr
Nov 7Colona, ILBackyard Ultra
Nov 13Delmar, IABackyard Ultra, 4 mi
Oct 17Danville, IA25K, 12K +1
Sep 18, 2027West Point, IABackyard Ultra
Nov 14Central City, IA6 hr
May 15, 2027Galena, IL8 hr, 4 hr
Sep 11, 2027Palo, IA45K, 30K +1
Nov 7Dubuque, IA50K, 25K
Oct 16Dubuque, IA100 mi, 100K
Dec 13Peoria, IL50K
Aug 14, 2027Dixon, IL15 mi, 10 mi +1
Apr 8, 2027Pekin, IL200 mi
Apr 17, 2027Crystal Lake, IL50K, 15 mi +1
Apr 17, 2027Dodgeville, WI50K, 27K +1
Build your aid station plan, organize your crew, and dial in your nutrition strategy. Everything you need to finish strong.
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