A ballot initiative to designate sections of the Gallatin and Madison rivers as “outstanding resource waters” is allowed to gather signatures after the Montana Supreme Court reversed a ruling by Attorney General Austin Knudsen that deemed the petition unconstitutional.

In a unanimous opinion published by the high court on Tuesday, the court said Knudsen’s “legal sufficiency” review that resulted in him blocking the proposal from going to the ballot was incorrect.

After Knudsen rejected the initiative, the three environmental groups behind the effort — Cottonwood Environmental Law Center, Gallatin Wildlife Association and Montana Rivers — petitioned the decision to the Supreme Court.

Before a ballot initiative can go out for signature gathering, the Attorney General must perform a “legal sufficiency” review. During the last legislative session, the definition of “legal sufficiency” was expanded from solely compliance with constitutional and statutory provisions to include “the substantive legality of the proposed issue if approved by the voters.”

According to the justices’ opinion, Knudsen said the ballot measure would be insufficient because it “unquestionably causes a regulatory taking by depriving affected property owners all productive or economically beneficial use of their land” and “imposes an uncompensated taking in violation of the Montana and United States Constitution[s].”

But, the court said there were two critical problems with the AG’s approach.

“First, it misapprehends and misapplies the law that applies to unconstitutional takings, and second, the approach contradicts the statutory scheme creating the Attorney General’s review process,” the unanimous opinion authored by Chief Justice Mike McGrath read.

In a concurring opinion, McGrath expanded on the second point.

“(Knudsen) lacks the power to reject a proposed ballot initiative based on an opinion about its constitutionality. Under our constitutional structure and separation of powers, only the courts may make determinations about a law’s constitutionality,” he wrote.

Knudsen argued that Initiative 24 would likely result in the seizing of private property, and for the ballot initiative to be valid, it must provide means of compensation to the private property owners. In both the U.S. and Montana Constitutions, there are provisions that say the government cannot take private property without providing compensation.

“But the Attorney General provided no authority for this proposition, and as a matter of takings law, it is incorrect,” the opinion read. “Nothing in I-24’s language impairs a person’s ability to seek full compensation. There is no constitutional need for I-24 itself to contain a mechanism for compensation because the mechanism already exists.”

The high court ordered Secretary of State Christi Jacobsen to approve the initiative for signature gathering. For the petition to appear on the November ballot, it must receive 30,000 signatures by June 17.

If approved, the section of the Gallatin River from the boundary of Yellowstone National Park to the confluence of Spanish Creek and the section of the Madison River from Hebgen Lake to Ennis Lake would be designated “Outstanding Resource Waters.” The designation would grant the rivers statutory protection from water quality degradation.

The initiative would also change a Montana statute that prohibits the Department of Environmental Quality from issuing new or increased point source discharge permits that would “result in a permanent change in the water quality of an outstanding resource water.” The statute under I-24 would modify to include temporary adverse water quality changes, according to the initiative’s language.