Science-Based Grizzly Bear Management Act of 2021 This bill directs the Department of the Interior to reissue the final rule relating to removing the Greater Yellowstone Ecosystem population of grizzly bears from the Federal List of Endangered and Threatened Wildlife, published on June 30, 2017 (82 Fed. Reg. 30502), without regard to any other provision of statute or regulation that applies to issuance of such rule. Such reissuance shall not be subject to judicial review. Interior shall issue a final rule removing the Northern Continental Divide Ecosystem population of grizzly bears from the Federal List of Endangered and Threatened Wildlife without regard to any other provision of statute or regulation that applies to the issuance of such rule. Such issuance shall also not be subject to judicial review.