I only ask because I've never come close to that because the most I can achieve is about a 10,000' differential in elevation. Our peaks are 14,000' but the radio line of sight is to stations that sit on the plains at 4,000' to 5,000'. The radio horizon for 10,000' difference in antenna height is about 140 miles.
But if I do peak-to-peak, like both of us sitting at 12,000' with me in Colorado and the other station in Wyoming or New Mexico, really long direct paths are possible. Otherwise I'm hoping for a topospheric duct to get the DX.
At 177 miles path loss at 144 MHz calculates to roughly -124 dB, so 7W (+38 dBm) and an EDZ (about +11 dB of gain) should produce around -75 dBm at the receiver, which is something like 40 μV of signal strength at 50 Ω even without RX antenna gain. Most radios these days have sensitivity down to around 0.2 μV, so the limit with VHF and UHF is mostly line of sight and not so much transmitter power.