As built in 1886, Three Sisters was 120.7 feet long, measured over the hull, exclusive of the extension over the stern, called the fantail, on which the sternwheel was mounted. The width or beam of the vessel was 30.2 feet, exclusive of the guards, and the depth of hold was 4.4 feet. Overall size of the vessel was 320.79 gross and 292.29 registered tons.