If it's not economically feasible to put a repeater on the other side of the hills, they shouldn't be able to count you in their DMA and you should be free to get feeds of your choice from a 3rd party provider (can't be Locast anymore since they're all but dead, but a similar concept fully legalized by new regulation to provide station coverage to people who can't get OTA).
The station owners are given FCC licenses to provide free OTA programming for their communities. Getting them as part of a cable/satellite package should be a convenience (for guide, DVR integration, etc.), not a necessity. There are too many stations claiming DMAs that their signals have no way of giving usable coverage to and expecting most of their viewers to sub to pay-tv providers that they can then gouge for retransmission fees.
EDIT: Yespage's idea above is even better for providing coverage for people who can't get OTA.