So you have two yagi's - one on the transmitter side of the hill and another on the house side in such a position that they can't 'see' each other. Join the two together with the correct impedance coax cable and on the transmitter antenna install an antenna amplifier driven from a 12volt gell cell and a solar panel. Another yagi on your house pointed at the downhill antenna - 1300 feet is not a great distance. You should be able to do the sums to work out the path loss vs antenna gain plus amplifier gain. A single frequency yagi with one reflector and maybe two directors shouldn't be that expensive . This one has good specs and you should be able to shorten the elements to bring it up to the 160MHz frequency - a similar antenna should be available in the US......
This thread has been an interesting roller coaster. OP wants be alerted to fires in the immediate area? Vagrant has the closest solution here, and I have done the same when in a very rough terrain area in high fire danger. This will work. You'll need a scanner in the house cranked up to full volume. If indeed sheltered by terrain, the scanner will remain quiet until something is happening right on top of you.
1. Listen to the assigned air tactics frequency for your area. Their transmissions will reach down into your hole, guaranteed, with any nearby fire. This might be too good though, and you might hear incidents that are of no immediate impact to your location. Defer to 2 and 3 then. 2. Listen to the assigned ground tactics freqs for your area. This will be low powered mobile and handheld simplex transmission on the fire line, which given your sheltered location, you'll likely only receive if a transmission is nearby. 3. Listen to the repeater input of your CalFire Local Net and when someone is close, you'll hear them. But this could be for any Calfire response in your area, including medical aids and traffic collisions.
PM me your location and I can get you all three of those freqs. I sort of live and breath calfire radio.