AERIAL SHOT of spring thaw with PAN left to interior of helicopter and two men in cockpit, of them reading map. MCU of pilot head to PAN left of out view of mountainous terrain and lakes. MCU of interior of cockpit. MS of frozen lake. PAN right along shoreline. PAN left of same with helicopter landing. MS of helicopter "Ranger" written on it, of technician getting out to prepare equipment for water test, of him taking water samples, getting in helicopter, rotor blades turning and helicopter taking off. LS of helicopter flying over lake and forest area, flying past camera, landing again, technician gets out with equipment and drills hole in ice. MCU of technician taking water samples, packing things back in helicopter and taking off. More shots of same to MS and MCS of helicopter pilot. FOLLOW MLS of geese in flight.