Procuring property

[Keaton Smith]

I own some property that a developer would like to develop on. The developer is interested in some other land that I have found, my question is what is the best way to lock up the land so someone cant get into the property. I would need to tie up the property for a while in order to get approval from the county for the proposed development. I'm just not sure how to write up a contract in order to tie up the property without telling the owner what the intentions are so they don't just do what I'm planning on doing.