The Outdoor Biology Instructional Strategies (OBIS) project began in 1972 to enable non-school youth groups (aged 10-15) to gain firsthand experiences in outdoor environments. This descriptive paper explains the program including its purpose and historical background. Specific objectives are to: (1) stimulate curiosity about local environments; (2) develop investigative and observational skills; (3) teach basic concepts of ecology; (4) help participants better understand their roles in ecosystems; and (5) provide exciting and educational outdoor experiences. The OBIS project uses a discovery approach in which active participants learn about such ecological topics as natural selection and food chains. Modules are divided into several one-hour activities with activity cards presenting: an overview, information summary, simple materials; outdoor conditions needed; step-by-step instructions; and optional activities. Specialized packets include the Trail Module and Camp Kit. Resource centers throughout the country have been established to promote the activities (with Florida's OBIS program highlighted). There is also an explanation of several phases in material development/evaluation. Reactions from teachers attending a summer institute indicate that they found the resource helpful in the classroom even though it was developed for non-school settings. (An appendix includes names and addresses of developers/suppliers and an extensive OBIS bibliography.) (DH)