According to "Journal Missouri Constitutional Convention of 1875" vol. 1, p. 104 (published 1920), Rucker moved to Rolla in 1889, where he was engaged in the timber and tie business. It further states that he died in Sturgeon on December 28, 1889.

FYI--A quick internet search for information on the Montana Constitutional Convention that Rucker was involved with indicates it took place April 9-14, 1866, so it would appear that his banishment to the Wild West took place very late in the war and that he remained there for a number of months after the end of the conflict.