Okay, I'm a little stumped.
Washington State about 4500 foot elevation, definitely looks mustelid, kind of otterish but too big (even though it is a slightly melted-out).
Much to big for marten, both loping and walking tracks.

My first thought was otter, but I've never seen an otter track that big, no trail drag mark, and no otter habitat anywhere near (I have seen otter tracks in odd places though).

Wolverine possibly?

Rather rare in this area, but not unheard of. I'm not really too familiar with wolverine tracks since I've only seen a few sets of them.
I'm not too sure about the size, are they too small for wolverine, also didn't notice much in the way of toenails.

Well, females are smaller. It looked like the track had 5 toe prints in it which they have. Not all the time do their toe nails show in the tracks. They do like to lope like the tracks in the picture for periods of distance and then revert back to a walk also.

Wolverine is the only thing I could think of, definitely five toes.
I'm guessing someone who has lots of experience could tell by the gait and distance between tracks??

Looks like female wolverine.

Ya, its easier to tell in person rather than pictures. You can notice the tracks where it is walking. They are not very far apart typical of a shorter legged animal. Not may animals due that loping gait also. I see no reason why you could not have the occasional wolverine down there in your higher country.

They are tireless in their travels and can cover a lot of miles. I can't think of many other animals that would leave tracks like that. It can't be any thing in the canine family as they all have 4 toes with a declaw that is high enough up it doesn't imprint. Same with felines. The tracks look too big for otter, plus no tail drag marks.

I am gonna say wolverine and as others have said it's hard to tell in a picture but after looking at the pattern in the middle photo I am going with gulo as that is typically the pattern when they are just travelling. Smaller set of tracks likely a female.

1st pic: 5 toed track as big as the palm of your hand.

2nd and 3rd pics, a 3,3,3 pattern (but is really 4,4,4).

4th pic: a 2,2,2 pattern.

All of these signs scream large mustelid. Tracks are too large, and obviously furred, to be otter. There is really only one conclusion. Probably an endangered species in Washington so you will have to quit using that area so as not to disturb them!!!
mt

Looks like wolverine to me. Hard to tell size in pic but if you've ever seen fisher tracks wolverine look like a larger version. Otter look pretty much the same without the hair between the toes. Too big for otter and haired pretty much equals wolverine. The few wolverine tracks I've seen are about the size of a half grown cougar. Is that about the size these tracks you found are?

Wolverine.

Looks like wolverine, to me. Pretty neat, given you found them down in Washington.

Nice pics wags !! Definitely not otter

Sure look like these small wolverine tracks to me