Naturally, as rock climbers, we really like rocks. At the core, they allow us to channel our inner primate and engage in an incredibly stimulating vertical endeavor. Specifically, we seek solid, featured rock that makes climbing possible. We want something we can step or pull on, wrap our heels around, jam our hands into, or at least obtain enough friction to hang on. In other words, we want to avoid heaping piles of choss.
While most of us aren’t geologists who study the composition and formation of rocks, we are climbers—and as climbers, rock quality and type matters. So, with a style of climbing in mind, let’s cover a few of the main ones:
Granite (and other granitic rock): A trad climber’s delight
Granite, an igneous rock created by slowly cooled magma hardened below ground surface, can be found in various forms. Generally, the rock has a coarse and grainy surface filled with quartz and feldspars that make it exceptionally solid. Luckily for us, the hardness of granite enables it to take shape in the form of mountains, cliffs, and domes—weathered overtime to lend us great features. The most common erosion occurs vertically, which delivers many happy climbers with wide cracks that are perfect for trad climbing.
Granite (or other grantitic rock) can be found in many of America’s most loved climbing areas, such as Yosemite Valley, Tuolumne Meadows, Joshua Tree NP, Rocky Mountain NP, Longs Peak, Looking Glass, South Platte, Black Canyon of the Gunnison, as well as Cathedral Ledge, Whitehorse Ledge, and Cannon Cliff in New Hampshire.
Sandstone: crack climbers’ rock of choice
Sandstone, a sedimentary rock formed directly over the surface of the Earth, can carry many different characteristics. Formed by a deposit of layered sediments compressed and hardened over millions of years, sandstone can often erode fairly easily. Nevertheless, it can also bring great friction, cracks, and other interesting features.
Some of the most popular sandstone-climbing destinations include Indian Creek, Moab, Zion NP, Corbin of Red River Gorge, Nuttall of New River Gorge, Red Rock National Conservation Area, and the Garden of the Gods.
Limestone: the ideal sport climbing rock
Limestone, also a type of sedimentary rock, forms underwater from the structures of living organisms like coral and shells. Composed of aragonite, calcite, calcium carbonate, silica, and finer sediments like clay, silt, and sand, limestone does not erode easily—thus providing a solid surface for climbing. You can expect vertical to overhanging cliffs and caves from limestone, making it the ideal rock for sport climbing.
Some of the best limestone climbing areas in the US include Shelf Road, Spearfish Canyon, Glenwood Canyon, Rifle Mountain Park, American Fork Canyon, and Mount Charleston. Thailand and many destinations in Europe offer world-renowned limestone climbing.