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 21, 2027 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
The half marathon course begins at the NAAC parking lot, leading athletes east along the W 64th Pkwy sidewalk, then north onto the path alongside Virgil Way. Athletes will then turn right (east) onto the Ralston Creek Trail to complete a 7-mile out-and-back section before joining a challenging counter-clockwise loop around Blunn Reservoir, ultimately returning to the venue. Eight aid stations and three toilets are strategically located along the route to ensure athletes stay fueled and refreshed.
10K
10K athletes will start from the NAAC parking lot and head east along the sidewalk on the south side of W 64th Pkwy then north on the path running alongside Virgil Wy to start the challenging counter-clockwise loop around Blunn Reservoir before returning to the venue. There are three aid stations and one toilet along the route to keep athletes fueled and refreshed.
5K
5K athletes will start from the NAAC parking lot and head east along the sidewalk on the south side of W 64th Pkwy to the first underpass and Ralston Creek Trail. Running northwest, with Blunn Reservoir on their right, athletes will turn around at 1.55 miles and return on this out & back course. Two 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 and modified placement 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 and modified placement 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 and modified placement credit towards the Run Amok Championship!
Weather Overview
These values represent the 14-year monthly averages for March in Golden.
About Golden
All-Out Spring Fever takes place in Golden, Colorado, United States. The local timezone is America/Denver.
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🏃 Plan Your Next Race in Golden
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- Golden Running Calendar 2026 See all upcoming race dates.
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.