Members of Congress are asking federal officials not to revoke protections for the gray wolf in sections of the lower 48 states where the predator remains on the endangered species list.

After nearing extinction in most of the nation, the wolf has rebounded so strongly in the Great Lakes and Northern Rockies that it's no longer classified as endangered there. Packs also have become established in Oregon and Washington, and restoration efforts continue in the Southwest.

The U.S. Fish and Wildlife Service is considering whether to drop the wolf from the endangered list in areas where none are known to exist.

A letter to the agency sent Tuesday by 52 U.S. House members says legal protections should remain because the wolf could continue expanding its territory elsewhere, benefiting the environment.