HELIX Environmental Planning (HELIX) conducted a due diligence biological assessment of the Kaiser Facility Expansion Project located in the City of Lancaster in Los Angeles County. The assessment included a site reconnaissance to evaluate biological resources and to identify potential biological limitations to site development. The site was evaluated for the presence of sensitive habitats, rare plants, burrowing owls, nesting raptors, Mohave ground squirrel, desert tortoise, and other species of concern. After the initial site visit, HELIX prepared a letter report that identified the existing biological resources and provided an analysis on their potential effect upon development of the five-acre site. The analysis included recommendations for future focused surveys, potential permitting requirements (federal, state, and local), and anticipated mitigation measures. It was determined that although significant biological impacts may occur from the project, impacts could be reduced to less than significant levels.