In 1857, Captain Underwood returned to the east for a time. When he returned to the west coast in the fall of 1858 he was sent to Fort Humboldt where the Bald Hills War was beginning. Captain Underwood led a detachment from Fort Humboldt to a post at Pardee's Ranch where they escorted pack trains over the Bald Hills to protect them from the attacks by the Whilkut. Later, Captain Underwood established Fort Gaston among the Hupa people on the Trinity River and commanded its garrison, a detachment from the U. S. 4th Infantry.