FM Fool only lets me build a 500 ft tower and that gets you only 90 miles.
It certainly does - it has terrain models and FCC data. There's a nerd section that explains the process.And the crazy part is you can only go up to 200 before you need FAA study and approval as well as registration.
Then again that may be a tool for designing a transmitter site.
Does that take in to account diffraction or anything else?