WASHINGTON, Feb. 2 (UPI) -- The U.S. Fish and Wildlife Service was expected to issue a proposal Thursday removing gray wolves in the northern Rockies from the Endangered Species List.

BOULDER, Colo., Feb. 23 (UPI) -- A series by UPI examining the relationship of humans to the environment. This week: Despite its longstanding bad reputation, wolves can work some wonders on local ecosystems.

The rebound of healthy populations of two large predators in the Rocky Mountains is forcing interests on both sides of the endangered species issue to rethink their definition of when an animal should be removed from the list.

The Bush administration's April 1 ruling to reclassify the North American gray wolf as a "threatened" species is helping to define a serious argument that remains about the purpose of the federal Endangered Species Act.