It's probably not just a look alike - it is a liatris. Most likely liatris aspera (rough blazing star) which are native to MN prairies.

I thought of that, but it does not have the punctuated bloom shape.

Is it more to the blue end? Perhaps Viper's Bugloss - Echium vulgare?

Purple? Lythrum salicaria (Purple loosestrife)
Pinkish-lavender? Epilobium augustifolium (Fireweed)

So far, purple loosestrife is the leading candidate, even though I haven't seen it in particularly moist locations. Are there any native Lythrums?

purple loosestrife info

Lythrum salicaria does grow on dry soil. When first introduced, it thrived in ordinary garden soil.

Yes, there are several native Lythrums in this country. Most are found farther south and along the coasts. L. alatum would probably be the only Lythrum native in Minnesota.