Arkansas vs Arkansas River

Arkansas

name
  • A river in the United States, rising in the Rocky Mountains of Colorado, and flowing generally southeast over 1,400 miles through Kansas, Oklahoma and Arkansas, where it joins the Mississippi in Desha County. 

  • A state in the South Central region of the United States. Capital and largest city: Little Rock. 

Arkansas River

How often have the words Arkansas and Arkansas River occurred in a corpus of books? (source: Google Ngram Viewer )