Sentinel Rock, rising 3,270 feet to the heavens from the base of the Yosemite Valley, was one of the most difficult natural monuments to photograph. On the south side of the valley, along the Merced River, Carleton Watkins found an accessible location and photographed the formation late in the afternoon, benefiting from the setting sun as it highlighted the trees along the riverbank. Though initially overwhelmed by the immensity of the landscape when he first arrived in California in 1851, Watkins went on to successfully render the dramatic scale of western landscape features-mountains, trees, deserts, and oceans.