I believe this is some type of Verbascum (Mullein)? Anyone know which variety? Here is a link that might be useful: Mullein

Ah, Melilotus officinalis (Yellow Sweet Clover), thanks!! B) It is a threat to recovering prairies because it easily invades open areas and may compete for resources with native species. It is similarly an unwanted invader of rocky, open, calcareous glades and woodlands. It can degrade natural communities by overtopping and shading native sun-loving species. Indeed! :/

Here's another one from an unkept field by a truck stop about ~2.5' tall...any idea what species these pics are of?

It's a goldenrod obviously. Not sure which one. I went through them all, and the species that looks closest to me is S. petiolaris, except the recurved phyllaries on petiolaris are very distinct, and even with the blurry picture, it looks like they are smooth, on this plant, but not sure because it is blurry.