| North Portland Harbor | |
| Map Size: | 300 |
| Pushpin Map: | USA Oregon |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of North Portland Harbor in Oregon |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Oregon |
| Subdivision Type4: | County, City |
| Subdivision Name4: | Multnomah, Portland |
| Length: | 5miles[1] |
| Source1: | Columbia River |
| Source1 Location: | about 108miles from the Columbia mouth |
| Mouth: | Columbia River |
| Mouth Location: | about 103miles from the Columbia mouth |
| Mouth Coordinates: | 45.63°N -122.7317°W[2] |
| Mouth Elevation: | 10feet |
The North Portland Harbor is an Oregon waterway or channel in Multnomah County, specifically in Portland. An anabranch, about 5miles long, of the Columbia River, it separates Hayden and Tomahawk islands from the mainland. Flowing generally northwest, the channel rejoins the main stem slightly upstream of Kelley Point Park and the mouth of the Willamette River.[1]
The Interstate Bridge carries Interstate 5 (I-5) over the channel, and farther downstream the Oregon Slough Railroad Bridge carries rail traffic. The BNSF Railway crosses North Portland Harbor over the rail bridge.[3]
Terminal 6 of the Port of Portland lies along the mainland shore of the channel. Northeast Marine Drive runs roughly parallel to the channel for much of its length.[4]
The official name registered with the United States Board on Geographic Names is North Portland Harbor, although historically other names have been applied. These include Oregon Slough[2] and Hayden Slough.[5]