SR 20 over Swinomish Channel
Good Condition45 years old18,383 vehicles/day
Location
| State | Washington |
| County | Skagit |
| Location | 9.3 E Island Co |
| Carries | SR 20 |
| Crosses | Swinomish Channel |
| Coordinates | 48.45636, -122.52186 |
Condition Ratings
| Overall Condition | Good |
| Deck | 7 (Good) |
| Superstructure | 7 (Good) |
| Substructure | 7 (Good) |
| Channel/Waterway | 8 (Very Good) |
| Scour Critical | 5 — Stable for scour |
Physical Characteristics
| Material | Steel Continuous |
| Design | Stringer/Multi-beam |
| Total Length | 3544.9 ft (1080.5 m) |
| Max Span | 246.1 ft (75 m) |
| Deck Width | 42.0 ft (12.8 m) |
| Deck Area | 13830.4 sq m |
| Main Spans | 5 |
| Year Built | 1981 |
Traffic
| Avg Daily Traffic | 18,383 (2023) |
| Truck Traffic | 6% |
| Lanes On Bridge | 2 |
| Lanes Under Bridge | 4 |
Inspection & Ownership
| Last Inspection | 123 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | 0011612A0000000 |