When the current state highway numbering system was first posted in January 1964, SR 220 began at Fort Simcoe State Park and headed east to Jct US 97 at Toppenish. In 1971, SR 220 was extended about half a mile east to Jct SR 22. Effective April 1, 1992, SR 220 was dropped from the state highway system.
Before 1964, SR 220 was SSH 3B.
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