What Coal Mine is this???

We passed a large coal mine in Montana. It seems that there were quite a large number of BNSF coal trains. What is the name of this coal mine and about how many trains does BNSF run to and from this mine? I am from the East and very unfamilar with the west.

If you could be a little more precise as to where, it would be help. I believe there are two: Big Sky Mine, and Decker. BNSF train symbols for those would be BSM and DKM respectively.

The mine was south of the Little Big Horn Monument. We were on a bus tour so I don't really know how far south it was. It seemed to parallel I-90 for a few miles. Could this have been the Powder River mine???

Here are the mines in Montana that the BNSF lists.

Absaloka Mine
Decker Mine
Rosebud Mine
Signal Peak Mine
Spring Creek Mine

I would place my bet on it being Absaloka or Rosebud, both of which are listed in Big Horn County, MT. It would be one of a dozen or so [further south and east in WY] located in the Powder River Basin.

I forgot to mention that there was a conveyor running across the highway feeding a power plant. Does that help?

It probably wasn't either Decker or Spring Creek because they are about 20 miles east of I-90 and quite a bit (60 miles or so) south of crow agency. You have to take a different highway out of Sheridan, WY to get there.
Rosebud is by Colstrip if I remember right which is also quite a bit north east of Crow agency, So I wouldn't think it'd be that one.
Absaloka might be the one you saw, even though if I remember right it's quite a bit northeast of little big horn though. I haven't driven to Billings for a while and have never really paid attention to what mines you can see off the interstate either.

it is rosebud in colstrip it has a conveyor going from west to east to a coal power gen plant. if you past a smaller coal power gen about 15 miles before that coming n to s.