Perched gracefully on the upper left flank of Big Rock’s Main Slab, the Upper Slab area offers climbers a balanced mix of moderate crack climbs and more demanding face routes that reward both the methodical and the bold. This zone serves as a strategic launching pad for those looking to extend their adventure — routes here make excellent second pitches for the climbs below or can be stitched together to form longer, satisfying single pitches. The solid rock and well-maintained bolts invite confidence, freeing your focus to savor the climb and catch sweeping views from 1,766 feet elevation.

Approaching the Upper Slab is straightforward, with well-worn paths accessible from established routes beneath—whether you’re coming from The Roof or venturing up Crater Maker (referred to by locals as the Dark Side of the Moon), the trail weaves through dry, rugged terrain typical of Southern California’s Inland Empire. The approach is manageable and well marked, ideal for a half-hour warm-up hike with GPS coordinates securing your way at latitude 33.83802, longitude -117.1725.

This stretch of Big Rock is equally rich in history and renewal. Rebolting efforts completed in 2018 replaced aging anchors and bolts with stainless steel Powers 5-piece bolts, ensuring solid protection and peace of mind on every climb. For those focused on classic lines, the Upper Slab features beloved climbs such as Left Flake (5.7), Right Flake (5.7), Cheap Thrills (5.10a), Mad Dogs (5.10b), and Let it Bleed (5.10c). Each present a reliable challenge without overreaching — the lower grades offer a comfortable testing ground, while the upper 5.10 routes keep the intensity tight for those pushing their limits.

Climbers visiting this area will appreciate the rock’s texture and quality, which holds well despite California’s dry climate. The rock type may not be specified, but the mountain’s lifetime of weathering has produced angles and cracks perfect for placing traditional gear, complemented by a solid rack of fixed anchors.

When planning your trip, consider the season carefully. Prime climbing windows align with cooler months and shoulder seasons around spring and fall, as the wall’s orientation ensures it warms quickly in the sun but can become baked during the summer heat. The main slab faces mainly southwest, so mornings start cool with shade lingering before direct sun moves over the rock.

Protection is straightforward but requires a good rack of trad gear, particularly a selection of mid-sized cams to handle the cracks. Bolts are plentiful and freshly upgraded, reflecting the area’s commitment to safety and sustainability. Descents are typically downclimbs or rappels from fixed anchors — always scout your line carefully and bring a plan for safe retreat, especially if combining multiple pitches.

Big Rock itself belongs to California State Parks’ Lake Perris State Recreation Area, blending accessible wilderness with quality climbing. Rock fans will find a welcoming environment with ample space to explore routes and absorb panoramic views across the Inland Empire. The park’s reopening and rebolting signal a bright future for local climbing, appealing to both locals and road-tripping adventurers.

For those preparing to visit Main Slab - Upper, pack comfortable approach shoes, a solid trad rack emphasizing mid-sized cams, and brushes for cleaning holds post-rain. Hydration and sun protection are vital, given the exposed granite faces and Southern California climate. Keep an eye on the weather forecast as precipitation is rare but can affect roots and dirt on approach trails.

Whether you seek the satisfying friction of the Left and Right Flakes or the more technical challenge of Cheap Thrills and Mad Dogs, the Upper Slab area delivers a diverse climbing experience without fuss. This is climbing grounded in honesty — routes that ask for steady technique and reward patience, all beneath open skies framed by panoramic vistas. Big Rock continues to carve its reputation as a reliable, scenic destination where the heart of California trad climbing beats strong.