The first pack was near Norris, 3 of them, all black, they were circling a herd of bisons. One was apparently a huge alpha male. We got a pretty good idea of its size relative to the bisons.
The second pack was in Lamar valley, near the Resaerch Institute. It's a mom(black) with 4~5 half-grown pups, some black some whitish.
Both times we needed 20X60 scope instead of 10X50 binocular. So there were no pictures. I talked to rangers afterwards and was told both were well known packs in their usual playground.