Founded by F. Beach Leighton in 1961 as F. Beach Leighton and Associates (FBLA), the company started out of his own home-office providing just engineering geology with a staff of only seven part-time employees. To better serve clients and for improved quality control of the geotechnical reporting, Beach decided to expand the firm's services to provide soils engineering. In 1972, Beach did this by establishing a new company that became the soils engineering arm of FBLA. In the same year, Beach formed another company that was devoted to applying geological sciences and soils engineering to environmental planning. By 1974, all three companies merged into one celebrating its new name, Leighton and Associates, Inc.