Best way to find out how much my vacant land is worth?

[Diana L.]

Hello,

I live in NYC and have owned 80 acres of vacant land in the state of Washington for about 10 years now. It is completely paid off and the only thing I pay are the yearly taxes. (which are minimal).

What is the best way to find out how much my land is actually worth? I have looked on Trulia and Zillow at vacant properties in the same county and it appears as if the price has gone up significantly from when I purchased it. What I am concerned about is if these vacant properties are actually selling. I am not in great need of the money, so I do not want to sell it for a low price. 

What I would like to do is possibly sell a portion of the land and do a 1031 exchange.

Are there any sites that show recent sold prices of vacant land? I contacted a few of the agents I saw as the listing agent on other properties in that county and nobody has responded.