[DonRotolo]

Yagis at both ends will give you plenty of link margin if it is only trees. I fear you are really hitting up against the speed of light.

WiFi has some very tight send-and-respond timing, particularly at high throughput. 1.1 km is a significant fraction of the ultimate limit for 802.11 distance, specifically because of the time it takes for the signal to travel - at the speed of light.

Oh, and your dish-on-a-pole-on-a-tower will come down in the first or second ice storm - you get those in PA, right? Don't ask how I know.

Oh, and what Al said about trees. (But, perversely, although a tree WILL grow, your antenna won't get any higher off the ground as it does).

I encourage you to learn about WiFi link timing and do the math for 1.1 km. You will be surprised at how tenuous that link is, but not for signal strength. Try 802.16 instead, built exactly for what you want to do.