 At the age of 18, Cotter asked Sutton for permission to go west and seek his fortune in the gold mines as some of the Suttons had done.Instead, scouts of the Whitney Surveying party offered him a job and Cotter took a position as packer on the California Geological Survey under Josiah Whitney from 1862 to 1864.Hired as a packer, Cotter did not actually know much about packing, but caught on quickly.