Adams |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2187 |
| Marilyn B. Ward | R | 2158 |
Asotin |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 3418 |
| Marilyn B. Ward | R | 2672 |
Benton |
| Candidate | Party | Votes |
|---|
| Marilyn B. Ward | R | 21117 |
| Robert S. O'Brien | D | 20184 |
Chelan |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 8881 |
| Marilyn B. Ward | R | 8509 |
Clallam |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 11940 |
| Marilyn B. Ward | R | 8607 |
Clark |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 35767 |
| Marilyn B. Ward | R | 31331 |
Columbia |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 947 |
| Marilyn B. Ward | R | 890 |
Cowlitz |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 15993 |
| Marilyn B. Ward | R | 8660 |
Douglas |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4423 |
| Marilyn B. Ward | R | 3750 |
Ferry |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1090 |
| Marilyn B. Ward | R | 691 |
Franklin |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5834 |
| Marilyn B. Ward | R | 4898 |
Garfield |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 759 |
| Marilyn B. Ward | R | 556 |
Grant |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 8796 |
| Marilyn B. Ward | R | 7669 |
Grays Harbor |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 15851 |
| Marilyn B. Ward | R | 8682 |
Island |
| Candidate | Party | Votes |
|---|
| Marilyn B. Ward | R | 9085 |
| Robert S. O'Brien | D | 7764 |
Jefferson |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4180 |
| Marilyn B. Ward | R | 2999 |
King |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 294094 |
| Marilyn B. Ward | R | 238135 |
Kitsap |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 31471 |
| Marilyn B. Ward | R | 25781 |
Kittitas |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5608 |
| Marilyn B. Ward | R | 3985 |
Klickitat |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 3219 |
| Marilyn B. Ward | R | 2312 |
Lewis |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 11439 |
| Marilyn B. Ward | R | 9600 |
Lincoln |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2607 |
| Marilyn B. Ward | R | 2320 |
Mason |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 7446 |
| Marilyn B. Ward | R | 5548 |
Okanogan |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 6411 |
| Marilyn B. Ward | R | 4927 |
Pacific |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4876 |
| Marilyn B. Ward | R | 2604 |
Pend Oreille |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1926 |
| Marilyn B. Ward | R | 1524 |
Pierce |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 92026 |
| Marilyn B. Ward | R | 66425 |
San Juan |
| Candidate | Party | Votes |
|---|
| Marilyn B. Ward | R | 2318 |
| Robert S. O'Brien | D | 1914 |
Skagit |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 15208 |
| Marilyn B. Ward | R | 13295 |
Skamania |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1652 |
| Marilyn B. Ward | R | 1052 |
Snohomish |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 68987 |
| Marilyn B. Ward | R | 57055 |
Spokane |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 70547 |
| Marilyn B. Ward | R | 63603 |
Stevens |
| Candidate | Party | Votes |
|---|
| Marilyn B. Ward | R | 5361 |
| Robert S. O'Brien | D | 5298 |
Thurston |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 28695 |
| Marilyn B. Ward | R | 23519 |
Wahkiakum |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1001 |
| Marilyn B. Ward | R | 504 |
Walla Walla |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 8837 |
| Marilyn B. Ward | R | 8379 |
Whatcom |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 22393 |
| Marilyn B. Ward | R | 18620 |
Whitman |
| Candidate | Party | Votes |
|---|
| Marilyn B. Ward | R | 7588 |
| Robert S. O'Brien | D | 7401 |
Yakima |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 27483 |
| Marilyn B. Ward | R | 26207 |