The National Survey of Fishing, Hunting, and Wildlife-Associated Recreation conducted by the Service with the Census Bureau is an excellent source of information about recreation participants and spending.
Banking on Nature written by Division economists shows the contribution of wildlife refuges to their local economies.
FWS Recreational Fishing Database is a searchable collection of metadata on studies of the value anglers place on fishing.
A Manual for Conducting Natural Resource Damage Assessment: The Role of Economics gives an overview of the NRDA process and explains the economics of it. The manual was written in 1995 and is obsolete in many respects.