Adams |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2857 |
| A. William (Bill) Gough | R | 1471 |
| Jack T. Perciful | OWL | 79 |
Asotin |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 3715 |
| A. William (Bill) Gough | R | 1596 |
| Jack T. Perciful | OWL | 113 |
Benton |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 21268 |
| A. William (Bill) Gough | R | 10445 |
| Jack T. Perciful | OWL | 718 |
Chelan |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 10840 |
| A. William (Bill) Gough | R | 4890 |
| Jack T. Perciful | OWL | 225 |
Clallam |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 12205 |
| A. William (Bill) Gough | R | 4402 |
| Jack T. Perciful | OWL | 558 |
Clark |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 40638 |
| A. William (Bill) Gough | R | 14736 |
| Jack T. Perciful | OWL | 1363 |
Columbia |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1220 |
| A. William (Bill) Gough | R | 611 |
| Jack T. Perciful | OWL | 14 |
Cowlitz |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 18614 |
| A. William (Bill) Gough | R | 4653 |
| Jack T. Perciful | OWL | 332 |
Douglas |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5608 |
| A. William (Bill) Gough | R | 2203 |
| Jack T. Perciful | OWL | 76 |
Ferry |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 999 |
| A. William (Bill) Gough | R | 366 |
| Jack T. Perciful | OWL | 38 |
Franklin |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 6330 |
| A. William (Bill) Gough | R | 2637 |
| Jack T. Perciful | OWL | 173 |
Garfield |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 925 |
| A. William (Bill) Gough | R | 451 |
| Jack T. Perciful | OWL | 9 |
Grant |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 10985 |
| A. William (Bill) Gough | R | 4363 |
| Jack T. Perciful | OWL | 375 |
Grays Harbor |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 17869 |
| A. William (Bill) Gough | R | 4196 |
| Jack T. Perciful | OWL | 800 |
Island |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 8581 |
| A. William (Bill) Gough | R | 3775 |
| Jack T. Perciful | OWL | 135 |
Jefferson |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 3766 |
| A. William (Bill) Gough | R | 1364 |
| Jack T. Perciful | OWL | 212 |
King |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 348107 |
| A. William (Bill) Gough | R | 117648 |
| Jack T. Perciful | OWL | 16652 |
Kitsap |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 36205 |
| A. William (Bill) Gough | R | 10495 |
| Jack T. Perciful | OWL | 1303 |
Kittitas |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 6376 |
| A. William (Bill) Gough | R | 2092 |
| Jack T. Perciful | OWL | 162 |
Klickitat |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 3553 |
| A. William (Bill) Gough | R | 1321 |
| Jack T. Perciful | OWL | 80 |
Lewis |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 13498 |
| A. William (Bill) Gough | R | 5742 |
| Jack T. Perciful | OWL | 457 |
Lincoln |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 3043 |
| A. William (Bill) Gough | R | 1591 |
| Jack T. Perciful | OWL | 109 |
Mason |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 8197 |
| A. William (Bill) Gough | R | 2254 |
| Jack T. Perciful | OWL | 297 |
Okanogan |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 7373 |
| A. William (Bill) Gough | R | 2776 |
| Jack T. Perciful | OWL | 224 |
Pacific |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5190 |
| A. William (Bill) Gough | R | 1336 |
| Jack T. Perciful | OWL | 221 |
Pend Oreille |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2022 |
| A. William (Bill) Gough | R | 858 |
| Jack T. Perciful | OWL | 56 |
Pierce |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 105495 |
| A. William (Bill) Gough | R | 32366 |
| Jack T. Perciful | OWL | 3800 |
San Juan |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1800 |
| A. William (Bill) Gough | R | 1232 |
| Jack T. Perciful | OWL | 113 |
Skagit |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 17348 |
| A. William (Bill) Gough | R | 7224 |
| Jack T. Perciful | OWL | 683 |
Skamania |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1763 |
| A. William (Bill) Gough | R | 567 |
| Jack T. Perciful | OWL | 46 |
Snohomish |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 77047 |
| A. William (Bill) Gough | R | 27987 |
| Jack T. Perciful | OWL | 2790 |
Spokane |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 79742 |
| A. William (Bill) Gough | R | 38892 |
| Jack T. Perciful | OWL | 3951 |
Stevens |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5285 |
| A. William (Bill) Gough | R | 2929 |
| Jack T. Perciful | OWL | 225 |
Thurston |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 32754 |
| A. William (Bill) Gough | R | 8116 |
| Jack T. Perciful | OWL | 1614 |
Wahkiakum |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1109 |
| A. William (Bill) Gough | R | 336 |
| Jack T. Perciful | OWL | 15 |
Walla Walla |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 10179 |
| A. William (Bill) Gough | R | 5337 |
| Jack T. Perciful | OWL | 296 |
Whatcom |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 24349 |
| A. William (Bill) Gough | R | 9862 |
| Jack T. Perciful | OWL | 1349 |
Whitman |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 8191 |
| A. William (Bill) Gough | R | 4802 |
| Jack T. Perciful | OWL | 623 |
Yakima |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 31173 |
| A. William (Bill) Gough | R | 14245 |
| Jack T. Perciful | OWL | 999 |