Upper Arboretum

Upper Arboretum is a bouldering area in California, about 0.7 miles from the town of Yankee Hill. It sits alongside other climbing at Lower Arboretum, Waterway West and Waterway Caves, all within about half a mile, which makes it easy to pair with those spots in one trip. The area is a bouldering destination, with 18 routes that range from the easiest V0 to the hardest V13. The median grade is V2, so the boulders here suit climbers of all levels, from beginners looking for simple holds to those working on more advanced problems. The Knifeblade arete project is among the most challenging routes, rated V13, while Autobahn is a V0 boulder for newcomers. The most comfortable months for a visit are typically May and October, when typical averages from a nearby weather station in Sonora run to highs around 76°F and only a few wet days. July and August are the hottest, with highs in the low 90s. For a change from climbing, the Summit Trail hike and the Creekside Trail mountain bike route both lie about 3 miles away. Paddlers can head to the Stanislaus River, roughly 6 miles off.