It is 18.12 miles (29.16 km) long and runs east–west, entirely within Umatilla County.

OR 334 was established in 2003 as part of Oregon's project to assign route numbers to highways that previously were not assigned, and, as of October 2020, was unsigned.

OR 334 begins at an intersection with OR 37 approximately ten miles north of Pendleton and heads east through Myrick.

After OR 335 turns north toward Helix, OR 334 then continues east through Athena, ending at an intersection with OR 11 approximately one mile east of Athena.

The entire route is in Umatilla County.