80 miles? If there was a radio that could do it, you sure as hell couldn't carry it.
For perspective, A cellphone tower has a range of about 15 miles. The FRS and GMRS "walkie talkie" radios (although some are marketed as up to 25 miles) really don't have near that in practical range. You'll be lucky to find a set which can provide reliable audio at 1 mile. 1/2 mile is more like it.
CB radio's with huge antennas and illegal boosters can hit like 10 miles. Typical stuff is more like 4 miles. And those certainly aren't portable.
So, the quick answer is no. However, as Chaticpinoy mentioned, this is the reason the "cellular" concept was invented. You might want to look into Nextel phones. They have the features of a walkie-talkie, but use the cellular network.