Rising prominently within the rugged walls of Combat Rock in Big Thompson Canyon, the Diagonal route invites climbers seeking a straightforward yet rewarding trad climb carved by natural lines and finger cracks. As you make your way along the worn trail that cuts through pine-scented forest, the approach reveals itself quickly—just a short hike to the base where the left-leaning corner crack sharply slices upward at a deliberate angle. This crack, the defining feature of Diagonal, promises engaging finger jams paired with footwork that calls for steady balance and careful placement.

The first pitch leads you through a sequence of technical spots, challenging your finesse with small cams and wired stoppers. Passing a scrappy little tree nestled beside the rock, you continue past a bulging hump, following the crack’s diagonal route up to a two-bolt belay stance approximately 30 feet higher. For those who prefer to cut down on rope drag, a third pitch can be slotted in just beyond the belay by moving 20 feet further to a fixed pin and setting up an anchor with stoppers, although many find the two-pitch version ample and satisfying.

The second pitch ups the ante, tracing the diagonal crack toward an overhanging flake that demands bold moves and larger pro, with #2 Camalots essential to secure this wider fist jam section. The climb continues with a powerful pull over the flake and a few easier moves along the face, finishing at another two-bolt belay. From here, rappelling down requires attention — carefully double-rope rappel to the first belay station; the alluring tree a climber might spot is out of reach, a subtle reminder to stay anchored in precise pathfinding. A final double-rope rappel brings you safely back to the trail below.

Combat Rock feels alive on this classic route: sunlight filtering through pine branches dapples the rock face, and the canyon’s breath stirs the needles beneath your feet. It’s a spot where solid climbing skills meet nature’s straightforward lines and provides a genuine sense of accomplishment. The climb suits those comfortable with traditional gear placements, who appreciate moderate difficulty balanced with varied crack techniques.

With a 5.9 rating, Diagonal strikes a practical sweet spot. The rock generally holds firm, though the footwork requires alertness as some edges are less than confident. The route’s moderate length and clear features make it a prime choice for climbers looking to sharpen their trad skills or enjoy a memorable day in Estes Park Valley. Gear-wise, aim for a rack heavy on smaller cams and wired stoppers for the lower pitch and pack a few larger cams to handle the wider jams overhead.

Timing your climb during spring and fall will keep temperatures comfortable and reduce the risk of slippery conditions. Morning ascents catch the wall in shadow before the afternoon sun warms the canyon, making hydration and sun protection essential once the day advances. Approach on sturdy footwear as the trail is straightforward but strewn with roots and loose rock. Your pack should carry two ropes for the double rappels and a solid helmet to guard against occasional loose blocks.

Diagonal is Combat Rock’s hallmark line: accessible, enjoyable, and packed with classic crack climbing that will give you the full range of Trad’s tactile, hands-on thrills. Whether you’re stepping up for the first time at 5.9 or honing your trad experience in the shadow of the Rocky Mountains, this climb offers an honest connection to the rock and canyon that few routes in the area match.