Unlike in the American Southwest, rock art and writing by Native Americans is scarce in the Sierra Nevada. Most of the archaeological evidence of indigenous peoples in the Yosemite region consists of morteros, a Spanish word for the grinding holes made in rocks. These holes were used by Native American tribes to pound piñon (pine) nuts into a coarse meal mush. Look for tell-tale holes in the flat surfaces of granite rocks all over the Sierra Nevada, including in Yosemite, Sequoia, and Kings Canyon National Parks.
If it’s petroglyphs (that is, writing and art inscribed into the surfaces of rocks, usually by pecking) that you’re interested in, there are a few panels hidden in Yosemite National Park’s Hetch Hetchy Valley. Petroglyphs are more common on the east side of the Sierra Nevada, however. There volcanic rock and lava flows provided a better canvas for Native Americans who left evidence of their passage through the area, including Paiute tribespeople in the Owens Valley.
Although Yosemite has few pictographs (literally, figures and designs painted on rock), you can find many by driving farther south in the Sierra Nevada to Sequoia National Park. There in the park’s foothills, at the bottom of the steep and winding Generals Highway, Hospital Rock and Potwisha campground both have pictographs and morteros that are easy to find. Hospital Rock is particularly rich in pictographs, leading some archaeologists to believe it was once a ceremonial gathering place for Native Americans (though its nickname came much later when a Western pioneer unluckily stumbled into a bear trap nearby.)