I've installed hundreds of UHF antennas that were 90 to 110 miles from San Francisco. To get great reception on UHF we used 40 foot masts on top of the house and either a long range UHF-VHF (say 10 foot or longer) antenna or a long range UHF only yagi (about 8 foot long) coupled to a medium priced preamp ( 20 db gain and under 5 db noise figure) and got great results. Typically the San Francisco UHF stations were better reception than the San Francisco VHF stations chiefly because the spectrum at UHF is quieter- meaning there's less man made noise and interferance at UHF to mess up the OTA reception. The power levels of the San Francisco UHFs run between 300K and 5 million watts which is typical of major market UHF stations. The San Francisco transmitters are only about 1500 feet above sea level but we had a clear shot to them with no mountains in the way.
I was once the tramsmitter technician for a rural Oregon TV tranlator site that picked up Portland Channels 6, 8, and 12 at 190 miles on the other side of 2 mountain ranges both with peaks over 8000 feet. Of course the receiving antenna was a multi wavelength copper wire rhombic which was streched between 4- 35 foot telephone poles that were situated in a diamond shape about 120 feet apart and located at about 5000 feet elevation. This antenna fed 1 watt VHF low band transmitters that gave the rural area up to 20 miles away their only TV reception as this was at the dawning of the big dish era around 1980.
Lots of Canadian cable companys used large antenna arrays to pick up ABC, NBC, and CBS stations from Northern US states often at distances over 200 miles with results that they were able to sell to their cable customers.
Bottom line is that with decent locations and home quality antennas and preamps 100 mile UHF reception is no big deal for a carefully installed setup at say 55 feet above ground level.