Idaho waters support the endeavors of 418,000 fishermen. Streams receive an estimated 56 percent of the total annual fishing pressure. In 1968, this amounted to 1,655,000 angler days and 12 1/2 million dollars expended for stream fishing. A large proportion of Idaho stream fisheries consist of wild fish populations. Unless free access is provided to spawning areas, valuable fisheries could be diminished or lost entirely. With today's emphasis on improved transportation, highway construction, timber access, etc., the design engineer plays an important role in the maintenance of our fisheries resources.