Chicago Basin 14ers
Chicago Basin 14ers – Sunlight Peak, Windom Peak, Mount Eolus, North Eolus
Aug 25–27
Colorado – San Juan Mountains – 14,059’ (Sunlight), 14,088’ (Windom), 14,083’ (Eolus), 14,039’ (North Eolus) – 40 miles, ~11,000 feet elevation gain
Best season: Summer to early fall | Trailhead: Purgatory Trailhead | No permit or parking fee required
Trail Overview
This Chicago Basin epic links four of Colorado’s most remote 14ers into one push: Sunlight Peak, Windom Peak, Mount Eolus, and North Eolus. The approach is part of the challenge, 13 miles in and 13 miles out from the Purgatory Trailhead with a full overnight pack before you even reach the alpine basin. The whole trip is approximately 40 miles round trip with nearly 11,000 feet of cumulative climbing.
I drove in Thursday night, parking near the Purgatory Trailhead, and began hiking Friday morning. With 40–45 pounds on my back, the 13-mile approach took me just shy of Chicago Basin, where I set up camp. The first 6–8 miles were euphoric, with pine-scented air, flowing creeks, and a good rhythm, but the final miles climbed sharply, and fatigue set in from lack of sleep. The bugs were fierce, and my sunscreen was no match for the swarms of flies.
Saturday began at 5 a.m., starting the hike at 6 to maximize daylight. This was the longest and hardest day, covering around 13 miles and 7,000 feet of elevation gain over 14 hours. Sunlight Peak came first, a steep, technical scramble with an exposed summit block. Windom Peak felt easy in comparison, with a straightforward Class 2 route. From Twin Lakes, I took a shortcut to Windom before returning for Eolus and North Eolus. Eolus offered sustained Class 3 and Class 4 scrambling, while North Eolus was a short side trip with expansive views of the Needle Mountains. I met only one other hiker who had matched my itinerary, both the four peaks and the full Purgatory approach.
Sunday was the hike out. Despite being “downhill,” my legs were wrecked, and the 13 miles dragged. It took about six hours to reach my car before the seven-hour drive home. By the end, the mental game was as demanding as the physical one, pushing through fatigue, soreness, and the looming drive ahead.
Notable Moments
Wildlife: Mountain rams were active and less skittish than usual. One ram held a brief standoff, pawing the ground and shaking its head before moving on.
Weather: Clear skies but strong sun exposure; forgot sunscreen on summit day, which made the descent and following day brutal.
Endurance Test: The 7,000 feet of gain on Saturday after a 13-mile approach put this in an elite class of single-day mountain efforts.
Mindset: I didn’t let myself feel accomplished until the fourth summit was behind me. Even then, the feeling was muted by exhaustion, though I still called my mother from the top.
Gear List
Backpack – 40–45 lbs fully loaded with overnight and summit gear
Tent, Sleeping Bag, Sleeping Pad – For two nights in the basin
Water System – Multiple bladders, extra bladder, filter
Cooking – JetBoil, freeze-dried meals, hiking snacks
Clothing – Long sleeve, short sleeve, windbreaker, hiking pants, leggings
Footwear – Durable hiking boots, toe socks for blister prevention
Poles – Essential for long climbs and descents
Protection – Bear spray, pistol, bear canister
Other Essentials – Bug spray, sun protection, navigation tools, med kit
Chicago Basin via Purgatory is not for the casual hiker. The approach is long, the elevation gain relentless, and the peaks demand focus and confidence in exposed terrain. But for those willing to carry in their gear, link four remote summits in one push, and carry it all back out, the reward is a true test of endurance and mountain skill in one of Colorado’s most spectacular alpine settings.
