family members." When the easement is donated at death, the estate gets, in addition to the exclusion and the benefit of lowered land value, a charitable deduction for the value of the easement.
If the will is silent about a conservation easement, the estate can elect the exclusion on a post-mortem basis, but this isn't a planning failsafe. The executor and/or heirs (depending on state law), along with a conservation organization, must agree to the terms of the restriction and finalize paperwork by the extended due date of the estate-tax return, and that's not always a deadline that can be met.