CORVALLIS, Ore. -- Biologists are reintroducing the endangered Fender's blue butterfly to a wildlife refuge south of Corvallis.
The butterfly is native to the Willamette Valley but is at risk because human development has constricted its habitat.
Federal officials say it was thought to be extinct until it was rediscovered in 1989.
The Corvallis Gazette-Times reports that a federal grant is financing restoration efforts at the William L. Finley National Wildlife Refuge.
A lupine plant the butterfly favors has been established at the refuge. This spring, researchers have been releasing larvae and butterflies at the refuge.
They say some of the larvae have been observed as adult butterflies.