The Jewel of the Sierra Nevada
November 7-8, 2026
Welcome to the 2026 Rio Del Lago Endurance Runs Presented by Altra!
🎉 Celebrating 25 Years of the Rio 100 & 5 Years of the Rio 50K!
The celebration is on! The Rio Del Lago Endurance Runs presented by Altra return on November 7, 2026, marking the 25th anniversary of the legendary Rio 100 Mile Endurance Run and the 5th running of the fan-favorite Rio 50K.
Whether this is your first Rio or your twenty-fifth, we’re doing cartwheels to welcome you to this milestone year. Together, we’ll honor a quarter century of endurance, community, and trail magic on one of Northern California’s most iconic courses.
🌄 About the Races
Rio 100 Mile Endurance Run presented by Altra
A true test of grit, determination, and heart. The Rio 100 takes runners on a breathtaking journey from Folsom to Auburn and back, showcasing miles of rolling singletrack, river views, and the rugged beauty of the Sierra foothills.
Rio 50K Endurance Run presented by Altra
Now in its 5th year, the Rio 50K starts alongside the 100 milers at Beal’s Point and follows the scenic early miles of the course. With stunning views along Folsom Lake, Lake Natoma, and the infamous Johnny Cash Trail, it’s the perfect distance for your first ultra or your fastest 50K yet!
🌟 A Milestone Year — A Legendary Experience
As we celebrate 25 years of Rio, expect an unforgettable weekend filled with tradition, camaraderie, and celebration. From world-class race organization and well-stocked aid stations to the warmth of our incredible volunteers, this year’s event will capture everything that makes Rio Del Lago truly special.
🎽 All Entries Include:
NorCalUltras Goody Swag Bag
Commemorative 25th Anniversary Technical Race Shirt
Finisher Medallion
100 Mile Finisher Belt Buckle (sub-30-hour finishers)
100 Mile Finisher Athleisure Lightweight Pullover
GU Energy Gels on Course
Skratch Hydration on Course
B-Tag Chip Timing
Bob and Brandt's Breakfast Bistro
Chef Tim’s “Soup for the Soul”
Dust Bowl Beer Garden
🏕️ Plan Your Race Weekend
Visit our official website for detailed race information, course maps, and lodging options in our host city of Folsom, California.
💛 Join the Celebration
Be part of history as we honor 25 years of the Rio 100 and 5 years of the Rio 50K — a milestone weekend filled with tradition, community, and endurance.
25 Years Strong. 25 Years of Grit. 25 Years of Rio.
We can’t wait to celebrate this special year with you on the trails!
– The NorCalUltras Team
Registration fees
Prices are inclusive of mandatory charges, items, and fees
100 Mile Endurance Run Spots remaining: 441
Price changes in 1 month 16 days-
-
Register for 100 Mile Endurance Run$413.90
Early Bird Pricing
Now registering Nov 14 – Jan 14 -
$467.40
Standard Pricing
Jan 15 – Sep 6 -
$494.14
Late registration
Sep 7 – Nov 2
-
50K Endurance Run Spots remaining: 199
Price changes in 1 month 16 days-
-
Register for 50K Endurance Run$162.48
Early Bird Pricing
Now registering Nov 14 – Jan 14 -
$183.87
Standard Pricing
Jan 15 – Sep 6 -
$210.62
Late Registration
Sep 7 – Nov 2
-
Cancellation Policy
Per the running industry policy, all entry fees are non-refundable & entries are non-transferable. Once we receive and accept your entry, you will not receive a refund if you cannot participate, you may not give or sell your number to anyone else, and you may not transfer your 2026 entry fee to a future race. This policy applies to all entrants and is in effect whether you are injured, have an unexpected family/business emergency, have a medical emergency, etc. If the course has to be changed or the race is cancelled due to an act of nature there are no refunds or rollovers. There are NO exceptions.
It is highly suggested that you purchase the Protection Policy.
Countdown to event
Contact information
- Event contact
- Fit 2 Run, Inc.
- Phone
- 9167656021
- Website
- Visit website
