List of highway route numbers in Oregon Mainline routes Mainline routes

| Number_ | South_west_end | North_east_end | Formed | Eliminated_ |
|---|---|---|---|---|
| Oregon Route 331 | I-84/US 30 southeast of Pendleton | OR 11 northeast of Pendleton | 2003 |  |
| Oregon Route 332 | Washington state line | OR 11 north of Milton-Freewater | 2003 |  |
| Oregon Route 334 | OR 37 north of Pendleton | OR 11 east of Athena | 2003 |  |
| Oregon Route 335 | OR 11 northeast of Pendleton | Helix | 2003 |  |
| Oregon Route 339 | OR 11 in Milton-Freewater | Towards Walla Walla, WA | 2003 |  |
| Oregon Route 350 | OR 82/OR 351 in Joseph | Imnaha | 2003 |  |
| Oregon Route 351 | South of Wallowa Lake | OR 82/OR 350 in Joseph | 2003 |  |
| Oregon Route 361 | US 97 southeast of Culver | US 26/US 97 in Madras | 2002 |  |
| Oregon Route 370 | US 97 north of Redmond | OR 126 in Prineville | 2002 |  |