Vacant land tax calculation vs. its usable portion?

[Ronald Roetsel]

All,

Based on your experience, would you say, that the real estate tax for a vacant land should be correlated with its usable part? 

Here's what I mean. One of my properties, specifically 10 acre, zoned single family, is located in the mountains. In fact, only 0.75 acre of it can be used - the rest contains of steep hills, cliffs, heavy rocks - no way that can be used for anything (I was fully aware of that). In the same area, there is 50+ lots, all with similar acreage, however, most of them are flat, some of them with with minor elevations. Unfortunately, the vast of them have houses and other buildings or improvements on them so I can't compare the public records. 

Question...  Is it fair to assume that hypothetical three neighboring vacant lots (1st totally flat = fully usable, 2nd - 50%-50%, 3rd = only 10% can be developed), with a similar acreage, should fall under different tax rates? Or that is irrelevant? 

Thanks!