This quarterly basin activity report is a summation of the drilling and testing activity in the four primary study areas and the USGS designated core sites of the Western Gas Sands Project (WGSP) (Figure l-1). Pertinent review information for April, May and June 1978, included for each study area, is divided into two sections. The core program section identifies industry activity within the USGS recommended core areas and relates the status of WGSP core acquisition developments. The second part, the activity section, details drilling and testing operations of interest to the WGSP throughout the entire basin or province. Newly staked or completed wells are listed in tabular form. Newly staked wells are shown on a map with yellow numbers and completed wells are shown with red numbers.