Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Melbourne Lake Dam | Dam | 239 | Mason | 47 29 53 N | 123 07 23 W |
| Merry Dam | Dam | 166 | Grant | 46 50 41 N | 119 51 22 W |
| Merwin Dam | Dam | 74 | Cowlitz | 45 57 24 N | 122 33 18 W |
| Meyer Dam Number One | Dam | 489 | Douglas | 47 26 23 N | 119 43 34 W |
| Meyer Dam Number Two | Dam | 484 | Douglas | 47 26 59 N | 119 44 16 W |
| Meyers Falls Dam | Dam | 463 | Stevens | 48 35 42 N | 118 03 28 W |
| Middle Pine Dike Dam | Dam | 683 | Spokane | 47 24 36 N | 117 32 22 W |
| Milewa Creek Dam | Dam | 2 | Pierce | 47 13 23 N | 122 40 34 W |
| Milk Pond Dam | Dam | 936 | Kittitas | 46 59 09 N | 121 03 34 W |
| Mill Creek Dam | Dam | 365 | Walla Walla | 46 03 53 N | 118 15 46 W |
| Mill Creek Diversion Dam | Dam | 385 | Walla Walla | 46 04 47 N | 118 15 16 W |
| Mill Pond Dam | Dam | 550 | Klickitat | 46 00 53 N | 121 13 10 W |
| Mill Pond Dam | Dam | 768 | Pend Oreille | 48 51 24 N | 117 18 22 W |
| Miller Reservoir Dam | Dam | 823 | Stevens | 48 16 30 N | 117 57 40 W |
| Milo Wood Pond Dam | Dam | 1144 | Chelan | 47 17 05 N | 120 20 22 W |
| Mineral Lake Dam | Dam | 434 | Lewis | 46 43 05 N | 122 10 40 W |
| Moccasin Lake Dam | Dam | 676 | Okanogan | 48 25 18 N | 120 12 22 W |
| Monroe Street Dam | Dam | 567 | Spokane | 47 39 42 N | 117 25 28 W |
| Monte Vista Poultry Detention Pond Dam | Dam | 77 | Thurston | 46 51 29 N | 122 58 16 W |
| Moran Slough Dike Dam | Dam | 139 | Grant | 46 38 29 N | 119 52 52 W |
| Morehouse Dam | Dam | 97 | San Juan | 48 36 35 N | 122 55 17 W |
| Morgan Hill Reservoir Dam | Dam | 79 | Jefferson | 48 07 29 N | 122 45 53 W |
| Moses Lake North Dam | Dam | 320 | Grant | 47 05 06 N | 119 19 58 W |
| Moses Lake South Dam | Dam | 320 | Grant | 47 04 49 N | 119 20 03 W |
| Mossyrock Dam | Dam | 129 | Lewis | 46 32 04 N | 122 25 34 W |
| Mount Adams Veneer Company Mill Pond Dam | Dam | 269 | Lewis | 46 30 41 N | 121 57 10 W |
| Mountain Lake Dam | Dam | 281 | San Juan | 48 38 59 N | 122 48 47 W |
| Mountain Spring Reservoir Dam | Dam | 21 | Pacific | 46 21 11 N | 124 00 47 W |
| Mud Mountain Dam | Dam | 300 | King | 47 08 27 N | 121 55 58 W |
| Muskrat Dam | Dam | 158 | Thurston | 46 49 17 N | 122 28 10 W |
| National Mill Pond Dam | Dam | 471 | Pierce | 46 44 53 N | 122 03 10 W |
| Nelson Dam | Dam | 234 | Clark | 45 44 53 N | 122 24 58 W |
| Newman Lake Flood Control Dam | Dam | 650 | Spokane | 47 46 06 N | 117 04 40 W |
| Nine Mile Dam | Dam | 501 | Spokane | 47 46 31 N | 117 32 39 W |
| Nisqually Trout Farm Dam | Dam | 4 | Thurston | 47 03 41 N | 122 43 46 W |
| Nooksack Diversion Dam | Dam | 492 | Whatcom | 48 54 23 N | 121 48 29 W |
| North Clear Zone Detention Dam | Dam | 87 | King | 47 28 11 N | 122 18 58 W |
| North Dam | Dam | 464 | Grant | 47 56 26 N | 119 01 02 W |
| North End Reservoir Dam | Dam | 133 | Pierce | 47 16 29 N | 122 30 46 W |
| North Fork Toutle Debris Dam A | Dam | 355 | Cowlitz | 46 18 53 N | 122 27 52 W |
| North Fork Toutle Debris Dam B | Dam | 342 | Cowlitz | 46 19 35 N | 122 27 46 W |
| North Hill Reservoir Dam | Dam | 663 | Spokane | 47 41 60 N | 117 20 34 W |
| North Scooteney Dike Dam | Dam | 282 | Franklin | 46 42 58 N | 119 02 35 W |
| Northwood Detention Pond Number One Dam | Dam | 690 | Spokane | 47 42 18 N | 117 18 10 W |
| Northwood Detention Pond Number Two Dam | Dam | 665 | Spokane | 47 42 12 N | 117 17 52 W |
| Nubgaard Dam Number One | Dam | 92 | Whatcom | 48 51 17 N | 122 37 23 W |
| Nubgaard Dam Number Two | Dam | 91 | Whatcom | 48 51 17 N | 122 37 17 W |
| Nysether Dam | Dam | 86 | Snohomish | 48 10 59 N | 122 17 11 W |
| O'Sullivan Dam | Dam | 318 | Grant | 46 58 57 N | 119 17 28 W |
| Oberholtzer Dam | Dam | 55 | San Juan | 48 28 17 N | 122 53 53 W |
| Obrien Dam | Dam | 186 | King | 47 43 47 N | 122 01 16 W |
| Oestreich Dam | Dam | 36 | Grays Harbor | 46 52 53 N | 123 41 23 W |
| Olason Reservoir Dam | Dam | 24 | Whatcom | 48 58 59 N | 122 42 23 W |
| Old Mill Pond Dam | Dam | 22 | Pacific | 46 40 17 N | 123 49 11 W |
| Olufson Dam | Dam | 45 | Pierce | 47 18 41 N | 122 39 40 W |
| Orrs Pond Dam | Dam | 56 | Island | 47 58 05 N | 122 21 41 W |
| Owen Dam | Dam | 49 | Kitsap | 47 43 35 N | 122 36 47 W |
| Owens Ponds Dam | Dam | 20 | Pacific | 46 39 41 N | 123 37 47 W |
| Owhi Lake Dam | Dam | 781 | Okanogan | 48 13 18 N | 118 53 40 W |
| Oxbow Lake Dam | Dam | 36 | Pierce | 46 58 59 N | 122 37 52 W |
| Packwood Dam | Dam | 872 | Lewis | 46 35 41 N | 121 34 04 W |
| Panakanic Water Works Dam | Dam | 588 | Klickitat | 45 53 17 N | 121 21 22 W |
| Parker Reservoir Dam | Dam | 509 | Yakima | 46 34 17 N | 120 43 46 W |
| Pat Owens Dam | Dam | 499 | Benton | 46 04 11 N | 119 08 46 W |
| Patterson Lake Dam | Dam | 732 | Okanogan | 48 28 02 N | 120 15 05 W |
| Pattie Prince Dam | Dam | 272 | King | 47 31 11 N | 121 53 40 W |
| Peabody Heights Reservoir Dam | Dam | 108 | Clallam | 48 05 53 N | 123 25 53 W |
| Pend Oreille County Pud Dam | Dam | 622 | Pend Oreille | 48 46 48 N | 117 25 04 W |
| Pend Oreille Mine Tailings Pond Dam | Dam | 723 | Pend Oreille | 48 53 12 N | 117 21 04 W |
| Perry Dam Number One | Dam | 722 | Douglas | 47 57 36 N | 119 17 52 W |
| Perry Dam Number Two | Dam | 726 | Douglas | 47 57 42 N | 119 17 46 W |
| Peters Reservoir Number One Dam | Dam | 637 | Okanogan | 48 23 48 N | 120 08 58 W |
| Peters Reservoir Number Two Dam | Dam | 587 | Okanogan | 48 23 36 N | 120 08 58 W |
| Peterson Pond Dam | Dam | 147 | King | 47 39 52 N | 122 01 11 W |
| Pilchuck River Dam | Dam | 156 | Snohomish | 48 01 05 N | 121 54 22 W |
| Pillar Rock Dam Number One | Dam | 83 | Wahkiakum | 46 15 47 N | 123 35 10 W |
| Pillar Rock Dam Number Two | Dam | 83 | Wahkiakum | 46 15 47 N | 123 35 10 W |
| Pinto Dam | Dam | 409 | Grant | 47 26 50 N | 119 15 02 W |
| Placer Lake Dam | Dam | 1631 | Yakima | 46 54 17 N | 121 28 52 W |
| Ponderosa Lake Dam | Dam | 729 | Stevens | 48 06 06 N | 117 26 52 W |
| Poplin Dam | Dam | 182 | Snohomish | 47 52 53 N | 121 44 34 W |
| Port Angeles Dam | Dam | 256 | Clallam | 48 02 11 N | 123 21 11 W |
| Portland Avenue Reservoir Dam | Dam | 71 | Pierce | 47 13 29 N | 122 24 40 W |
| Powell Dam | Dam | 121 | Lewis | 46 30 29 N | 122 42 34 W |
| Power Lake Dam | Dam | 745 | Pend Oreille | 48 14 24 N | 117 21 46 W |
| Pratt Dam | Dam | 20 | San Juan | 48 29 29 N | 123 01 35 W |
| Preston Mill Pond Dam | Dam | 123 | King | 47 31 17 N | 121 55 40 W |
| Price Reservoir Dam | Dam | 148 | Clark | 45 36 11 N | 122 22 04 W |
| Priest Rapids Dam | Dam | 128 | Kittitas | 46 38 35 N | 119 54 34 W |
| Prince Dam | Dam | 141 | Thurston | 46 49 47 N | 122 33 04 W |
| Printz Basin North Dike Dam | Dam | 165 | Pierce | 47 11 47 N | 122 07 58 W |
| Printz Basin South Dike Dam | Dam | 166 | Pierce | 47 11 41 N | 122 08 04 W |
| Prison Farm Sewage Lagoon Dam | Dam | 27 | Pierce | 47 13 11 N | 122 41 10 W |
| Prosser Dam | Dam | 189 | Benton | 46 12 47 N | 119 46 22 W |
| Quilceda Creek Dam | Dam | 45 | Snohomish | 48 07 35 N | 122 08 17 W |
| Quilceda Trout Farm Dam | Dam | 71 | Snohomish | 48 07 41 N | 122 07 59 W |
| Quilomene Creek Dam | Dam | 291 | Kittitas | 47 06 41 N | 120 03 58 W |
| Raatz Dam | Dam | 505 | Lewis | 46 29 05 N | 122 21 28 W |
| Raden Dam | Dam | 36 | Island | 47 59 17 N | 122 32 17 W |
| Rainbow Lake Dam | Dam | 672 | Columbia | 46 18 54 N | 117 39 40 W |
| Rainbow Springs Dam | Dam | 63 | Snohomish | 48 06 17 N | 122 00 22 W |
| Rains Dam | Dam | 29 | Clallam | 48 06 05 N | 123 21 23 W |
| Rat Lake Dam | Dam | 510 | Okanogan | 48 10 36 N | 119 48 28 W |
| Ravensdale Pit Dam | Dam | 183 | King | 47 20 53 N | 121 59 40 W |
| Raymond Heights Reservoir Dam | Dam | 35 | Pacific | 46 40 29 N | 123 43 17 W |
| Rearing Pond Dike Dam | Dam | 136 | Grant | 46 38 11 N | 119 52 28 W |
| Redmond Reservoir Dam | Dam | 99 | King | 47 42 47 N | 122 03 22 W |
| Reed Dam | Dam | 31 | Pierce | 47 20 47 N | 122 39 22 W |
| Reflection Lake North Dam | Dam | 567 | Spokane | 48 00 18 N | 117 17 04 W |
| Reflection Lake South Dam | Dam | 557 | Spokane | 47 59 30 N | 117 17 22 W |