A new study by government scientists says wind energy facilities have killed at least 67 golden and bald eagles in the last five years, but the number could be much higher.
The research represents one of the first tallies of eagle deaths attributed to the nation's growing wind energy industry. A total of 85 eagles were killed at wind farms since 1997, the study concludes, but most of those occurred in 2008-2012. Most deaths - 79 - were golden eagles.
While the birds are protected by federal law, the Obama administration has yet to file criminal charges against a wind energy company for killing any eagles.
Earlier this year, the Osage Nation expressed its opposition to a proposed wind farm in northern Osage County.
Wind Capital Group says it wants to build 94 windmills on land near Burbank. The group has applied for an eagle take permit from the US Fish and Wildlife Service.
The tribe says the project would harm the eagle population.
A trade group, the American Wind Energy Association, said the figure was lower than other causes of eagle deaths.
The Associated Press contributed to this report.