thumb|right|280px|map of the maumee river watershed showing st. marys river. the st. marys river (shawnee: kokothikithiipi ) is a u.s. geological survey. national hydrography dataset high-resolution flowline data. the national map, accessed may 19, 2011 tributary of the maumee river in western ohio and eastern indiana in the united states. prior to development, it was part of the great black swamp. today, it drains a primarily rural farming region in the watershed of lake erie. it is formed in southern auglaize county in western ohio by the confluence of the short east branch and center branch. it flows briefly west to st. marys, approaching to within two miles of grand lake before turning to the north. in northwestern auglaize county it turns sharply to the west-northwest, flowing past rockford and willshire into adams county, indiana. in northeastern indiana it flows northwest past decatur, then enters fort wayne. it hooks around in its last half mile (0.8&nbsp;km) to join the st. joseph river from the west to form the maumee in downtown fort wayne. the world war ii-era us navy vessel st. mary's river was named after this river. ==see also== * list of indiana rivers * list of rivers of ohio ==references==   
Landforms_of_Adams_County,_Indiana Landforms_of_Auglaize_County,_Ohio Landforms_of_Mercer_County,_Ohio Rivers_of_Indiana Rivers_of_Ohio Tributaries_of_Lake_Erie