The Owens Valley is home to the critically endangered Owens Pupfish (Cyprinodon radiosus). Threatened by the introduction of sportfishing species into the Owens River, the entire population of Owens Pupfish were removed from the river and relocated to carefully protected springs nearby. Sharing the freshwater ecosystems at this western edge of the Great Basin is the Coyote Willow (Salix exigua), which is also a host plant for the Mourning Cloak butterfly (Nymphalis antiopa). The Desert Spiny Lizard (Sceloporus magister) and Great Basin Snaketail dragonfly (Ophiogomphus morrisoni) also live in this delicately balanced ecosystem.