 However, the public interest stimulated by the Alaskan project is credited with influencing the purchase of Alaska from the Russian Empire on March 30, 1867, for $7.2 million.Cotter then joined Clarence King on the Geological Exploration of the Fortieth Parallel in 1867, resigned after two years and settled in York just outside Helena, Montana.In 1875, he traveled to Washington Territory and kept a short diary.