Growing up in Oregon, raccoons were a familiar sight. They lived in the abandoned orchard behind my house, and I'd see them and their distinct tracks down at the slough where I fish. Raccoons aren't native to Alaska, but there have been a number of attempts to introduce them. Raccoons were introduced in the late 1920s or early 1930s by fur farmers to Long Island, near Kodiak. They persisted for a few years but have not been seen for decades and are presumed to be extirpated.
In Southeast Alaska, eight raccoons from Indiana were released on Singa Island near Prince of Wales in the early 1940s. These were Melanistic raccoons, with black fur, and their descendants were reportedly seen into the 1990s. There have been no sightings in recent decades.
In 1950, raccoons of unknown origin were released or escaped on Japonski Island near Sitka. They were seen for years around the garbage dump by the Sitka airport until the early 1970s but haven't been seen since.
Raccoons were introduced to Haida Gwaii in British Columbia and spread to nearby islands where they have seriously impacted colonies of nesting seabirds. These non-native predators could've inflicted similar damage had they become established in Alaska.