Roswell was part of the 2nd Company of Ten led by Ezra Taft Benson. He left the company on 3 June at Fort Laramie to take a message to the Mormon Battalion sick detachments and Mississippi Saints at Pueblo, Colorado. In Wilford Woodruff's journal, his name is spelled as "Stephens." At some point he returned to Winter Quarters. He is seen crossing the plains again in 1851 with the Smith Company.