Perched near the base of Eldorado Canyon's West Ridge, Allosaur stakes its claim in a rugged corner of The Amphitheater, a spot that beckons trad climbers with a taste for commitment and careful footwork. The approach is straightforward—follow the West Ridge trail past the bouldering traverse, then scramble across slabs for a few minutes until you reach the south-facing wall marked by a solitary juniper tree that signals the start of this three-pitch adventure.

The first pitch climbs steeply and steadily to the left, threading a thin line toward a lone fixed pin about 25 feet up. The rock whispers caution here: protection is sparse and small, relying on offset Aliens and RPs. Even though the Eldorado guide rates this section at 5.7, climbers often find it skews into 5.8 territory, thanks to the sustained, vertical facework and runout nature. Finishing this pitch at a fractured purple band of broken rock, you’ll feel the line’s challenging personality, where solid holds demand precise moves and mental focus.

Pitch two veers upward and right, slipping into a left-leaning corner where small to medium cams provide reassurance. The crux hits near the top where the corner tightens, stepping into 5.8 difficulty. The belay sits comfortably on a ramp above the corner, well protected with medium cams and readying you for the final push.

The third pitch builds on that momentum, again shifting right into a left-leaning corner that arches into a roof. The crux here is more technical and solidly protected at 5.9, challenging climbers to use every ounce of balance and finger strength. This short 40-foot stretch ends atop the ridge, where the climb’s exposure unfurls with clear views of the canyon below.

Rappelling off Allosaur requires attention to detail: the rappel rings lie 30 feet west of the summit. Descending involves two rappels, first about 50 feet to a ledge, then a longer 100-foot drop that deposits you roughly 20 feet left of the original start. A 60-meter rope is highly recommended to navigate this safely without unnecessary rope swapping.

Allosaur offers a compact but demanding experience, blending solid, well-featured rock with sections of runout protection that reward climbers who are confident in their skills and gear placements. The climb demands both mental and physical commitment, especially on the first pitch, where hesitation or poor gear can turn enjoyment into anxiety. It's a quintessential Eldorado route—bold, accessible, and thoroughly satisfying for trad climbers wanting a taste of the West Ridge’s character.

Planning this route means packing a full rack with cams up to a size 2 Camalot, small gear including offset Aliens and RPs. Be precise with your protection placements, especially early on, where the margins are slim. The approach trail is solid but expect some cross-slab scrambling that can feel exposed if you rush. For timing, aim for morning to midday climbs when the sun warms the south-facing wall, but watch for late afternoon shadows that cool the rock and tighten your grip.

Allosaur rewards careful preparation and steady movement with the kind of gritty satisfaction climbers crave—the tangible result of navigating a route both exposed and technically engaging, where the canyon’s presence feels both imposing and exhilarating. With three well-defined pitches balancing steep face climbing and jammed corners, Allosaur remains a standout testpiece on the West Ridge that doesn’t ask for much but gives back plenty in experience and views.