This Public Works Technical Bulletin (PWTB) presents practical guidance on how to identify terrestrial archaeological sites that are good candidates for investigation (including an evaluation of their eligibility for the National Register of Historic Places) using geophysical survey techniques. Geophysical techniques have many applications for marine archaeological sites, but these are not included here. This PWTB also provides guidance on selecting geophysical techniques that are appropriate for use at particular sites. It is designed for use by cultural resource managers, other land managers, and archaeologists who have little or no previous experience in the use of geophysical techniques. The emphasis here is on helping such individuals avoid wasting time and money on surveys that have relatively little probability of success because of unfavorable site conditions or the use of inappropriate methods.