Get phone signal where there's no signal
Google Earth is actually quite helpful without fussing with drones at getting a pretty good idea of the profile along a path. You have to look for it, but it's there in the detailed information about the path. Bring up GE, find you, find the tower, draw a path. There are probably other programs, but that's the one I happen to know and use. Radio signals do not propagate through dirt (or very poorly) so you need the antenna high enough that it can see the antenna at the other end.

Antenna towers of any significant height are expensive and can be hazardous if not built correctly (thus, expensive - cheaper to construct a properly engineered expensive at the outset tower than to have a large cheap home-made antenna tower fall on people, houses, vehicles...)

Solar panels, a charge controller and batteries are often the best source of power for an off-grid antenna system. Fueled generators are expensive to run, long-term. Solar systems are expensive at first, but inexpensive to run if properly constructed.

Generically, you are looking at (normally antenna) tower construction. Wireless Internet Service Providers (WISPs) might be another path to investigate. 

Coming to an arrangement with landowners of the top of one of the hills, and along the path from your house to the top of the hill may be considerably cheaper than building a large antenna tower.

For smallish antenna towers, sometimes a large flagpole will work. Many of those are arranged so that the pole can be easily lowered to the ground, making it comparatively easy/safe to install and maintain the device on the top of them. Other towers need to be climbed, and that is a hazardous occupation in and of itself.