Sprague Lake critter

About 10 ft ahead on the path, some gentlemen -with lenses that cost more than all of my cameras and lenses put together- were taking some photos of trout in the stream. I saw some motion near our feet...

Glad to have actually seen one of these little critters in the wild, sad that this is the best picture that I got. It was very quick, darting between and around rocks next to the stream, then finally ran across the path, along a rail fence, and disappeared into the brush. At Sprague Lake, Rocky Mtn Natl Park CO.

IMAGE LINK: https://flic.kr/p/MxLx​Ap

I'm from Indiana, which may or may not mean anything, but I have no idea what that thing is. Help me out. Looks like a streamlined racing rat.

very fitting description LOL

It's a weasel.

Hey, thanks. We have weasels in Indiana. The one's I've seen have pony-tails, chase ambulances, and spend a lot of time waving a J.D. around.

Nice grab shot!

Congrats! Great shot!

It looks like an American martin.

Thanks for the comments everyone.

When I first saw it, I was thinking marten due to similarity to pics that others have posted. But after looking on the computer, I'm pretty sure it is a weasel (or stoat might be more correct name ) As evidence, here is the only other "clear" image, a skinny little black-tipped tail.
And the size, wild guess maybe a foot long ?