Although it once was, by far, the longest river of North America, today its length is comparable with the Mississippi River because of channelization of its waters to eliminate meanders and facilitate boat travel. The lower Missouri valley has become a highly productive agricultural and industrial region. Barges shipping gravel, wheat, fertilizer, and other grown, mined or manufactured products provide much of the commerce on the river today. In response to the growing amount of water traffic, federal and state agencies including the U.S. Army Corps of Engineers (USACE) heavily dammed and channelized the river in the 20th century. Although this development has contributed to the economic growth of the region, it has taken a toll on the ecology and the water quality of the Missouri.
His most productive years came with Boston, where he won 24 games from 1956 to 1958, averaging 138 innings each season. After that, he appeared strictly as a reliever and saved a career-high 11 games for the Senators. In a seven-season career, Sisler posted a 38–44 record with a 4.33 ERA in 247 appearances, including 29 saves, 12 complete games, one shutout and 656⅓ innings. Sisler retired from baseball after the 1963 season to become an investment firm executive, a career that lasted for over 30 years, retiring as a vice-chairman for A. G. Edwards.