During the night of 14 April, the troops of the 1st Cavalry moved with the rest of the command to invest the Modoc stronghold, and in the Second Battle of the Stronghold, 15–17 April, succeeded in cutting off the Modoc defenders' access to Tule Lake, their only source of water. During the night of the 16th, the Modoc abandoned their position and disappeared into the vast lava beds to the south. The 1st Cavalry lost two men killed and two wounded. On April 21, Col. Gillem was relieved of duty and replaced by Col. Jefferson Davis, 23rd Infantry, on May 2.
