If you decide you want to conserve your land and retain ownership of it, or sell all or a portion of it once conserved, you are likely going to use a tool called a conservation easement.
A conservation easement is a legal, voluntary, agreement between a landowner and land trust such as Tug Hill Tomorrow Land Trust, or a municipality, that creates a conservation plan and corresponding goals and restrictions to achieve those goals.
The agreement addresses future sub-division, whether or not additional house sites will be reserved, sensitive areas on the property that may need additional attention, and current and future uses on the property that would be compatible with conserving the land.
Public access is not required as part of a conservation easement project, although you can incorporate it as you feel appropriate. Incorporating trail access, if it made sense given your property, might increase your federal and/or state tax deductions.