a u.n. watchdog agrees. the first batch could fill three olympic size swimming pools. 31,000 tons of water will be released by next march. critics charge the long-range impact is unclear. in tonight s eye on america, a closer look at the icon of the american west: the bison. 60 million bison once robed north america. cbs of the yamaguchi reports on the enormous efforts to reintroduce this majestic animal to native amamerican tererritor. repororter: at ththe fort pek inindian reserervation inn monta bibison calf j just a fewew h hd is the newewest member ofof onef the fifirst herds s to rome thee asassiniboine e sp 26 landnds ie thanan a centuryry. > this mumust be very speciar you. my y generationon never gotoo grow up aroround buffafalo. now m my childrenen and my grandchihildren are e able t to witness himim b being on ouour hohomeland. repeporter: robbibie magnan manages s fort peckk reservatit- aa bison hererd starteded 20 yes ago t that has n now grown t to.