Ultramarathons in Lakewood

Saturday, October 3 · Lakewood, Colorado

The Bear Chase 100K is a five-loop trail race held each October at Bear Creek Lake Park in Lakewood, Colorado. Each loop covers approximately 12.4 miles with around 870 feet of climbing, giving runners familiar terrain to settle into while tracking their progress throughout the day. The course runs almost entirely on single-track dirt trails and soft surfaces, winding through varied terrain that includes forest sections, open meadows, and ridge climbs up to nearly 5,800 feet elevation. Runners pass through changing landscapes as they circle the park, moving between shaded areas and more exposed sections. The route is considered fast by ultra standards and not overly technical, though the repetitive nature means any small discomforts tend to compound over multiple loops. With a 16-hour cutoff and aid stations every 3-4 miles, this race works well for first-time 100K runners who want predictable logistics and the mental boost of seeing crew frequently. The loop format also suits runners who prefer knowing exactly what's ahead rather than navigating constantly changing terrain. Those looking for remote wilderness or significant technical challenges might find the suburban park setting and manageable elevation gain less appealing.