Immediately following his arrival in California in March 1868, naturalist John Muir set out for the Yosemite area,[53] where he found work tending to the sheep owned by a local rancher, Pat Delaney. Muir's employment provided him with the opportunity to study the area's plants, rocks, and animals;[53] the articles and scientific papers he wrote describing his observations helped to popularize the area and to increase scientific interest in it. Muir was one of the first to suggest that Yosemite Valley's major landforms were created by large alpine glaciers, contradicting the view of established scientists such as Josiah Whitney, who regarded Muir as an amateur.[39]