The scientific name of Hudsonian Godwit (Limosa haemastica) literally translates as "muddy bloody", the first from its habitat the second from the colour. Hudwit is what birders tend to call it, at least in Britain, where the other two godwits are abbreviated to Blackwit and Barwit.
It is quite a scarce North American shorebird and is classed as near-threatened by IUCN. It breeds only in five well scattered areas ranging from northern Alaska to the shores of Hudson Bay. It winters in southern South America but has regular stopover sites in North America, including southern Alaska where I photographed this individual in full breeding plumage. It has several spring stopover sites but in autumn the entire population gathers in Hudson Bay before making the journey to South America, probably in a single flight.
It is most similar to our Black-tailed Godwit but has darker red underparts and diagnostic black underwings. There was one larger bird in a flock of five in non-breeding plumage that really did look like a Black-tailed Godwit. But when it flew it had a black underwing. I may post a picture of that bird some time.