Complex sentence: Mount Tyndall was first climbed on July 6,1864 by Clarence King and Richard Cotter who were members of the California Geological Survey and under the overall direction of Josiah Whitney and the field leadership of William Brewer.
Split into simpler sentences: Mount Tyndall was first climbed on July 6,1864 by Clarence King and Richard Cotter. They were members of the California Geological Survey, under the overall direction of Josiah Whitney and the field leadership of William Brewer.