Alien Heads, located in Colorado's Quarry area along Thunder Ridge, offers a straightforward yet gratifying trad climbing experience on the South Platte. This single-pitch 5.9 route sits on the right side of the wall, featuring two fixed bolts supplemented by natural gear placements up to 2 1/2 inches. The climb invites adventurers to test their crack and face climbing skills on solid rock with reliable protection, making it a solid choice for climbers stepping up from easier 5.8 routes or those looking for focused practice on placing gear under moderate technical stress.

The approach to the route is accessible through the well-traveled trails of Thunder Ridge, set amid pine and aspen groves that breathe both calm and vitality into the surroundings. As you make your way to the base, expect a gently sloping path with some loose rock patches beneath your boots, rewarding you with clear views of the wall and the cascading creek below. The elevation here hovers around 7,000 feet, lending a crispness to the air that heightens focus with every move.

Alien Heads demands attentive gear placement, with protection options blending fixed bolts and natural placements, encouraging climbers to develop confidence in their rack-building and anchor setting. The route’s length and single-pitch nature make it an efficient choice for climbers looking for a solid climb without extended commitment. The rock itself feels steady under hand and foot, with a mix of finger cracks and pockets that require controlled strength and precise footwork.

Though not the most star-studded route in the area, Alien Heads stands out for its no-nonsense style and reliability. It suits climbers who value pure trad experience without distractions — a playground for honing skills, celebrating solid ascents, and appreciating the quiet pulse of Colorado’s outdoor climbing scene. Plan your visit considering the afternoon sun bathes the route, warming the granite and eliminating morning chill. Hydration is key here; carry enough water and ensure your footwear grips well to handle the mix of slab and crack climbing.

Local climbers praise it as a friendly introduction to moderate trad difficulty on a well-established wall, making it an ideal step before venturing into longer or more sustained routes nearby. Whether you arrive solo or in a small group, Alien Heads promises clear beta, manageable protection challenges, and a rewarding taste of South Platte climbing that leaves you eager for more ventures in this venerable climbing corridor.