Actually, the proposed exchange is a value for value exchange involving 18,066 acres of Trust land for 20,920 acres of federal land.  "Final acreages will be determined by the appraised value of the land finally selected to be included in the exchange. The appraisal process is set forth in the Federal Land Exchange Statute.

http://mhtrustland.wpengine.com/wp-content/uploads/2015/05/USFS-AMHT-EXCH-Proposed-Land-Exchange.pdf 

See this link on the Trust website for more complete information about the proposed exchange.