In late 2007, citizens, groups, and public officials in the Mid-Columbia region of Southeastern Washington state identified the need for a regional open space and trails plan that takes a more comprehensive view than the isolated city and county plans we now use.These entities came together to form a working group known as the Ridges to Rivers Open Space Network Steering Committee to start a public discussion, create a local vision, and plan for our future. They began a process to look on a regional level to see how best to use our natural assets to benefit our economy; provide access for recreation,education, and health; and preserve natural and aesthetic values.

There is no line on a map that defines where the Mid-Columbia is, just as open spaces are not defined or limited by jurisdictional boundaries. The area contains parts of Benton, Franklin, and Walla Walla Counties primarily in the vicinity of the metropolitan areas of Kennewick, Pasco, Richland, West Richland, Finley, and Benton City. It generally extends from the Saddle Mountains and the Hanford Reach National Monument to the north to the Columbia River to the south and from the Palouse and Snake Rivers to the east to the Rattlesnake Ridges and Horse Heaven Hills to the west.

The concept of open space is not uniformly defined from one jurisdiction to another. Some jurisdictions do not have a definition at all. One goal of the Ridges to Rivers Open Space Network steering committee and board of directors is that a definition be adopted a cross all jurisdictions as a key step toward facilitating cross-jurisdictional planning and dialog.