UPDATE: Since the subject property could never be developed in any way and the deed restriction is hunting, fishing and limited recreational use only I felt the only option I had was to do matched pair analysis on properties wit surplus land. Conservation easements allow at least one SFR home to be built so I couldn't use those. I found four sales with less than five acres and four similar homes with fifty to sixty acres and arrived at the value that way. I know it was an unconventional method but it was, I felt, the only credible option I had although it was admittedly flawed. My commentary is below for anyone interested and may find yourself in a similar situation.
"This report is prepared with the following conditions and criteria:
The subject lot cannot be subdivided.
The subject lot cannot be developed and can only be used as recreational including hunting and fishing.
There is a small cabin of unknown condition on site which has no contributory value.
The subject is served by a prescriptive easement and the extra ordinary assumption is made that it is permanent and cannot be revoked.
The sales comparison approach is the preferred approach to valuation. There were no sales located that are similar to the above referenced conditions. Most conservation easements allow at least one SFR structure and therefore are not considered comparable; also they are not typically reported in a verifiable manner. Properties listed and sold as hunting land typically are not restricted as is the subject. The method applied in this report is based on surplus land. Surplus land is land that is not needed for the existing use but cannot be separated and sold off. Surplus land is not needed for the existing use but, due to various factors like zoning restrictions or lack of access, cannot be sold off separately. For example, a large lot where the extra land is not accessible or where zoning prevents subdivision would be considered surplus land. The appraiser would need to consider how the surplus land contributes to the overall property value, but not as a separate, marketable entity.
In order to calculate the value adjustment to apply properties were located with surplus land and compared to similar properties without surplus land. The value per acre was derived and applied in this report. The properties used were zzz.
Typical rural residential SFR properties have up to five acres and properties with more acreage have what is considered surplus land. After the adjustments for property characteristics which were minimal because the properties were similar, it was determined that the value per acre for the surplus land was $zzz per acre and this was used as the basis for the site adjustments made in this report.
The HABU is the current use (recreational hunting and fishing) because it is not legally permissible to develop the land in any way. There were no sales located in a three county area that had the same restrictions as the subject. The basis for comp selection was acreage and the rational and basis for the adjustments was the derivation of per acre value for surplus land."
