Thank you both for your quick replies. I'm looking into those now.

Getting my dad to ACV isn't to difficult, we're in WAS, but my aunt is at SDF and it's been alittle more challenging finding flights for her.

I looked at the NW site (she has a voucher from them) but they are saying that neither NW nor any of their partners fly from SDF to ACV, which doesn't make much sense to me since she can fly from SDF to SFO and SFO to ACV.

Oh, well. I'm still searching.