For comparison — professional UHF radio with 4 watts can reach through 1 mile of densely populated area with lots of trees. If you spend more than $60 you might get 4 or 5 watts. Keep in mind that IF you had a 5 watt radio, compared to .5 watt, you’d get 10 times the coverage, but only three times the distance.
https://www.amazon.com/Midland-LXT600VP3-Channel-Two-Way-Privacy/dp/B007B5ZR4G

