Set against the cool, shadowed face of Sumas Mountain Crag in British Columbia’s Fraser Valley, Beware of Boulder (B.O.B.) carves a route up a fractured left arete that demands respect and focus. The climb stretches 60 feet along a slab cloaked in shade for much of the day, lending an almost contemplative atmosphere where the rock’s quiet textures come alive beneath your fingertips. The defining feature is not just the line itself but the large, jagged boulder wedged firmly in a crack to the left—an obstacle and landmark that gives the route its name and personality. From the hike in, expect the tranquil humidity of forest air mingling with the faint sound of distant wildlife, setting a calm stage before the technical engagement begins.

The route’s crux appears early, testing climbers’ ability to read the fractured line and pick subtle holds before the movement flows upward into steadier terrain. Climbing on this slab demands both precision and patience; slippery edges hint at the mountain’s slow erosion and the quiet battle it plays with time and gravity. The protection consists of five bolts leading to a two-bolt anchor—sport and top-rope friendly—providing solid security but requiring thoughtful clipping and continuous attention to rock quality.

The approach is refreshingly straightforward. A brief hike through the verdant Fraser Valley leads you to the base, where this north-facing wall keeps you cool and shielded from direct sun during peak hours. The elevation gain is moderate, making it accessible for climbers looking to combine light scrambling with technical climbing that sharpens crack and slab skills. The presence of the boulder wedged in the crack is more than just a visual cue—it alters the climbing dynamics, forcing minor route adjustments and adding an element of unpredictability to the line.

Practical preparation is key here. Given the shaded slabs can remain damp for much of the day, consider footwear with reliable rubber and plan your climb for late morning or early afternoon when the rock firms up after the dew. Hydration is always important, but the cool atmosphere of this wall helps reduce overheating risks, letting you focus on balance and body positioning.

Sumas Mountain Crag sits within a quiet corner of the Fraser Valley, drawing climbers who appreciate focused climbs with straightforward access and an environment that encourages mindful climbing. The protective bolts are well maintained, but the rock deserves respect—fractured sections can challenge traditionally minded protection placements if top-roping isn’t preferred.

Beware of Boulder (B.O.B.) offers a neat blend of old-school slab climbing with a unique line, and it rewards attentive climbers with an engaging experience framed by the stillness of British Columbia’s forested ridges. Whether you're setting up sport leads or keeping things safe on TR, this climb presents an excellent opportunity to sharpen technique on slab while soaking in the quiet power of the mountainside.