The development of parks across Canada was only possible because the male labourers were paid below market wage and had no other job opportunities. Thousands of men worked for the Parks Department from 1914 to 1915. These men included relief workers during the Great Depression and prisoners of both World Wars. Harkin was satisfied with his new work force because he was able to pay them twenty-five cents a day, while the daily wage in an isolated camp was two dollars. This labour wage differential caused a protest at Yoho Park, where the men refused to work as market wages had increased to twelve dollars a day while they continued to receive twenty-five cents. The situation escalated beyond Harkin's control and caused him to ask the Department of Defense to take over; the men responded by a failed attempt to dig their way out of the park and escape. Eventually, the camp was closed and the men were released.