DENVER — Does a river — or a plant, or a forest — have rights?

This is the essential question in what attorneys are calling a first-of-its-kind federal lawsuit, in which a Denver lawyer and a far-left environmental group are asking a judge to recognize the Colorado River as a person.

If successful, it could upend environmental law, possibly allowing the redwood forests, the Rocky Mountains or the deserts of Nevada to sue individuals, corporations and governments over resource pollution or depletion. Future lawsuits in its mold might seek to block pipelines, golf courses or housing developments and force everyone from agriculture executives to mayors to rethink how they treat the environment.

Several environmental law experts said the suit had a slim chance at best. “I don’t think it’s laughable,” said Reed Benson, chairman of the environmental law program at the University of New Mexico. “But I think it’s a long shot in more ways than one.”

The suit was filed Monday in Federal District Court in Colorado by Jason Flores-Williams, a Denver lawyer. It names the river ecosystem as the plaintiff — citing no specific physical boundaries — and seeks to hold the state of Colorado and Gov. John Hickenlooper liable for violating the river’s “right to exist, flourish, regenerate, be restored, and naturally evolve.”