THE MCLAREN TAILINGS SITE IS LOCATED IN PARK COUNTY, MT., JUST EAST OF COOKE CITY, MT. THE SITE ENCOMPASSES APPROXI- MATELY 10 ACRES. ORE FROM THE MCLAREN MINE WAS PROCESSED PRIMARILY FOR GOLD AND SILVER EXTRACTION USING A CYANIDE LEACHING PROCESS AT THE SITE FROM THE 1870'S TO 1952. THE TAILINGS WERE DEPO- SITED ON THE VALLEY FLOOR OF SODA BUTTE CREEK WHICH ORIGIN- ALLY MEANDERED THROUGH THE AREA CURRENTLY OVERLAIN BY THE MILL TAILINGS. THE EXTENSIVE FIRES IN YELLOWSTONE NATIONAL PARK IN 1988, WHICH REDUCED VEGETATION IN VICINITY OF THE SITE, AND THE ABOVE NORMAL SNOWFALL DURING THE WINTER OF 1989, CREATED THE POTENTIAL FOR MUCH GREATER THAN NORMAL RUNOFF IN THE PARK AND THE POSSIBILITY OF FLOODING LATE IN THE SPRING OF 1989. HIGHER THAN NORMAL STREAM FLOWS WERE EXPECTED WITHIN SODA CREEK AND THIS INCREASED THE LIKELIHOOD OF A WASHOUT AND CATASTROPHIC COLLAPSE OF THE TAILING DAM, IT WAS BELIEVED, WOULD RESULT IN SEVERE ENVIRONMENTAL DEGRADATION IN THE AREA SURROUNDING THE SITE AND POSSIBLY YELLOWSTONE NATIONAL PARK.