Rio Del Lago 100 Mile + 50K Endurance Runs 2025

About Rio Del Lago 100 Mile + 50K Endurance Runs 2025

The Jewel of the Sierra Nevada

November 6-7, 2027

Welcome to the 2027 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, 2027. Whether this is your first Rio or your twenty-sixth, 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

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!

🎽 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

• Neversecond Gels on Course

• Skratch Hydration on Course

• B-Tag Chip Timing

• Bob and Brandt's Breakfast Bistro

• Chef Tim's "Soup for the Soul"

• 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.

📋 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 Refund Protection Policy.

💛 Join the Celebration

We can't wait to celebrate with you on the trails!

-The NorCalUltras Team