There are three Miami Rivers, one in Florida, one in New York and one in Oregon. In addition, the Great Miami River and the Little Miami River are tributaries of the Ohio and the Maumee River is referred to in the Ohio Constitution as the Miami River of the Lake. Any help you could give us in narrowing this down would be greatly appreciated.

Columbia River is north of Oregon. - Lea

the Umatilla river

The Willamette River is the longest river "in" the State of Oregon. The Columbia and Snake are both much longer but are not completely "in" the State of Oregon.

The Grammart river flows north, and it is in Oregon.