Lange's metalmark butterfly (28747200334)

Antioch Sand Dunes, Aug. 30, 2016
USFWS Photo/Steve Martarano
Listed as Endangered under the Endangered Species Act, this species is in danger of extinction throughout all or a significant portion of its range.

Lange’s metalmark butterfly was historically restricted to sand dunes along the southern bank of the Sacramento-San Joaquin River, and is currently found only at Antioch Sand Dunes in Contra Costa County. Most of the habitat is now part of the Antioch Dunes National Wildlife Refuge (administered by the Don Edwards San Francisco Bay National Wildlife Refuge Complex). Recent population counts have ranged from several hundred to more than a thousand individuals. However, a steeply declining trend in the last 10 years, with a peak flight count of only 45 individuals in 2006 led to the implementation of several recovery actions, including aggressive habitat restoration and captive propagation of the butterfly.