Connect point A to Point B - ATT all brains

Hi All

Iv been going mad trying to figure out how to connect point A to point B for network access.

Point A to Point B is 12km - 16km

Weather conditions are shocking in Dallas.

Cannot lay cat5 or 6 from point A to B, far too expensive. Site is extremely remote.

Wifi is somewhat impossible due to a massive mountain between the 2 points.

Climate is crazy...winds, snow etc

Do have a power line going from point A to point B.

Point A has a 50mb internet connection and point B has 1.5mb, Each connect to their own junction box...extremely slow

Any ideas?