The Missouri River is slowly resuming its role as a transportation corridor for commodities such as grain, scrap metal and fertilizer, but proponents of the barge industry acknowledge they’re still swimming upstream against a perception that the river is not reliable enough to be profitable.

Some small, private barge companies never stopped using the river but public ports along the nearly 760-mile span from Sioux City, Iowa, to St. Louis, Missouri, disappeared in the late 1990s and early 2000s after a combination of drought, economic recession, low commodity prices and politic infighting led shippers to turn to rail and trucks.

As prices stabilized and droughts eased, attention turned to reopening some public ports, with the Woodswether terminal port in Kansas City last August being the first since 2007.

About an hour north, the St. Joseph Regional Port Authority is improving its infrastructure and plans to attract…