Directs the Secretary of the Interior, acting through the Director of the National Park Service, to: (1) perform a blood test of each bison in the herd inhabiting Yellowstone National Park for brucellosis; (2) vaccinate and restrain under quarantine restrictions each bison that tests negative for brucellosis in accordance with a protocol established under Idaho, Montana, and Wyoming law, to prevent transmission of brucellosis to susceptible animals; (3) slaughter or neuter each bison that tests positive for brucellosis, each bison that cannot be tested, and each bison that tests negative but cannot be restrained under quarantine restriction and make the carcass or neutered bison available for use by Indian tribes and other suitable recipients; (4) engage the services of a team of independent range scientists to determine the optimum population of bison that the land available for the herd in the Park is capable of sustaining; (5) identify locations outside the Park that would be suitable for sustaining herds of bison created from any excess number of bison in the Park's herd that are certified as being free of brucellosis; and (6) after brucellosis has been eradicated, continue to reduce the population of the Park's herd to a number that is approximately 500 below the optimum population by transferring the excess number of bison to locations identified in this Act.

Requires the Secretary, after December 31, 1998, to ensure that the number of bison in the Park's herd does not exceed the optimum population determined under this Act.