All-Out Spring Fever
About this race
All-Out Multicourse is proud to host our 15th Annual Spring Fever, a rewarding event for both novice and experienced athletes set against the backdrop of Table Mountain and the stunning Colorado foothills. This spring celebration, featuring our mascot Buzzby, includes 5K, 10K, and half marathon courses that trace the scenic shores of Arvada's Blunn Reservoir via the Ralston Creek Trail. Conveniently accessible from nearby highways, Spring Fever is the endless series spring counterpart to Kooky-Spooky, and proudly benefits our NEW charity, People and Pollinators Action Network (we really love the bees). And don't miss that you can use Spring Fever to qualify for your BOLDERBoulder wave!
Join fellow runners on March 23, 2025 for the All-Out Spring Fever. It's a fantastic Half-Marathon, 10K, 5K featuring a flat and fast course in Golden.
Pick your distance
Running
Half Marathon
Half marathon athletes will depart the east end of the NAAC parking lot then run along the sidewalk on the south side of W 64th Pkwy to reach the 2nd underpass and the path that runs adjacent to the west side of Virgil Wy. Turning right to go east on Ralston Creek Trail, half athletes will complete a 7 mile out & back dogleg before rejoining the counter-clockwise Blunn Reservoir loop. Going under the underpass at the reservoir entrance, athletes will make their way back up onto the 64th sidewalk then return the way they came to the finish line. 8 opportunities to fuel up (+ 3 toilets).
10K
10K athletes will depart the east end of the NAAC parking lot then run along the sidewalk on the south side of W 64th Pkwy to reach the east underpass and the path that runs adjacent to the west side of Virgil Wy. Athletes will continue north until just past Tucker Lake, then west and south, following Ralston Creek Trail around Blunn Reservoir going under the west underpass to return they way they came into NAAC and the finish line. 3 opportunities to fuel up (+1 toilet).
5K
5K athletes will depart the east end of the NAAC parking lot then run the sidewalk on the south side of W 64th Pkwy to reach the underpass and Ralston Creek Trail. Running northwest, with Blunn Reservoir on their right, athletes will turn around and return on this out & back course. 2 opportunities to fuel up.
VIRTUAL Half Marathon
Participate virtually! Get all of the SWAG, including a distance medal, shipped to you the week after the event, maintain eligibility for series finisher award and alumni brag tags, and get distance credit towards the Run Amok Championship!
VIRTUAL 10K
Participate virtually! Get all of the SWAG, including a distance medal, shipped to you the week after the event, maintain eligibility for series finisher award and alumni brag tags, and get distance credit towards the Run Amok Championship!
VIRTUAL 5K
Participate virtually! Get all of the SWAG, including a distance medal, shipped to you the week after the event, maintain eligibility for series finisher award and alumni brag tags, and get distance credit towards the Run Amok Championship!
Weather Overview
These values reflect historical conditions on the race dates in Golden in 2025, from Open-Meteo archive data.
About Golden
All-Out Spring Fever takes place in Golden, Colorado, United States. The local timezone is America/Denver.
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Race information has been sourced from the event's official website and other publicly available resources. For the most up-to-date details, please refer to the official website directly. If you notice any incorrect or missing information, don't hesitate to reach out to us by email.