Tenaya Canyon and Yosemite Valley (IMAGE) University of California - Berkeley Caption Tenaya Canyon (center) and part of Yosemite Valley (foreground) as seen from Glacier Point in Yosemite National Park. Tenaya Creek likely started to scour this granite canyon below Half Dome (center right) about 5 to 10 million years ago, with glaciers arriving about 2.5 million years ago to sculpt the classic glacial valley outlines. Credit Greg Stock/National Park Service Usage Restrictions none License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.