Seven environmental and animal rights groups are suing the Trump administration for its regulations that would make drastic changes to the implementation of the Endangered Species Act.
The environmental law group Earthjustice filed the joint suit Wednesday in San Francisco.
They charge the administration with breaking the law by announcing changes to the implementation of the landmark act without first analyzing the effects the changes would have.
"In the midst of an unprecedented extinction crisis, the Trump administration is eviscerating our most effective wildlife protection law," the National Resources Defense Council said. "These regulatory changes will place vulnerable species in immediate danger - all to line the pockets of industry. We are counting on the courts to step in before it is too late."
An Interior Department spokesman responded by saying "We will see them in court and we will be steadfast in our implementation of this important act with the unchanging goal of conserving and recovering species."
Attorneys general from two states - California and Massachusetts - also say they will sue.
Environmentalists credit the 1973 Endangered Species Act with saving numerous animals, plants and other species from extinction.
About 1,600 species are currently protected by the act and the administration says streamlining regulations is the best way to ensure they will stay protected.
"The revisions finalized with this rule-making fit squarely within the president's mandate of easing the regulatory burden on the American public without sacrificing our species' protection and recovery goals," Commerce Secretary Wilbur Ross said last week.
The finalized changes include requiring consideration of economic cost when deciding whether to save a species from extinction. The law currently says the cost to logging or oil interests will have no bearing on whether an animal or other species deserves protection.
The revised regulations would also end blanket protection for a species listed as threatened, a designation that is one step away from declaring it endangered, and reduce some wildlife habitat.
Conservation and wildlife groups call the changes U.S. President Donald Trump's gift to logging, ranching, and oil industries, saying they take a bulldozer through protections for America's most vulnerable wildlife.
A number of congressional Democrats have also denounced the changes, including New York Senator Chuck Schumer and House Speaker Nancy Pelosi,
Republican President Richard Nixon signed the act into law in 1973 as part of the response to the new environmental awareness sweeping the country in the early 1970s, which included Earth Day and the Clear Water and Air acts.