[3] The vessel also possessed all the modern machinery for quick loading and unloading of cargo from five large hatches, including ten winches and eleven booms.

The sea trials were held on December 2–3 and after their successful completion the ship sailed into San Pedro to load part cargo destined for East Asia.

While Haleakala was nearing her completion, she was allocated by the Shipping Board to Pacific Mail Steamship Company to operate between California and India.

The ship loaded part of her cargo at Los Angeles which consisted mostly of general merchandise but also included hundreds of American-made motorcycles and fifty automobiles and continued to San Francisco.

[10] The vessel made a short stop for bunkers at Honolulu where the crew was given a warm welcome and taught how to properly pronounce their ship's name.

Aside from her regular oriental cargo, the ship carried back home a large number of various exotic animals such as monkeys, orangutan, tigers and a 100 year old elephant destined to be sold to zoos around the country.

During the trip an elephant died and had to be buried in the ocean, and monkeys got free and the crew was forced to shoot the orangutan when he tried to engage the reverse gear.

[13] On her way back Haleakala also met another Shipping Board steamer, SS West Selene, who lost two of her propeller blades and was drifting helplessly.

[15] After conducting one more trip to India and the Philippines, Pacific Mail Steamship Co. returned Haleakala to the USSB in October 1920 due to significant overabundance of available tonnage and scarcity of cargo.

[16] At about the same time, Sudden & Christensen decided to charter a steamer for one trip from the Pacific Northwest to the United Kingdom and chose to take Haleakala as she was readily available.

[21] She reached Buenos Aires on July 6, and then continued on to Rosario and Rio de Janeiro loading various cargo such as fertilizer, manganese ore and coffee.