North Canadian River A river rising in northeast New Mexico and flowing about 1,300 km (800 mi) generally southeast to the Canadian River in eastern Oklahoma. It is known as the Beaver River in the Oklahoma Panhandle and as the Oklahoma River in Oklahoma City.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.