SALT LAKE CITY — The Navajo Nation filed a federal lawsuit Thursday against San Juan County, claiming its three established voting districts violate the constitutional rights of tribal members living in Utah.

The lawsuit filed in Salt Lake City's U.S. District Court asks a federal judge for an injunction that would force county commission district boundaries to be redrawn ahead of the November election.

No hearings have been scheduled in the case.

Deputy County Attorney Walter Bird didn't immediately return a call seeking comment on the lawsuit.

In court papers, attorneys for the tribe and six of its Utah members contend the current boundaries allow non-Indian voters to hold majorities in two of three districts.

The complaint also says boundary lines have not been redrawn since 1984 and that county commissioners have failed to address changes in population, despite U.S. Census data from 1990, 2000 and 2010.

Population figures included in the court filing show that residents in two of three districts represent about 29 percent of the total population. In the third district, Navajos represent nearly 93 percent of the population. Two of the districts have similar populations of about 4,600 people, but one has more than 5,300. Based on census data from 2010, each district should have about 4,900 residents, according to court papers.

"Because the populations in the three districts are not equal, the votes of residents are not equal in weight," court papers state.

Navajos make up just more than 50 percent of San Juan County's population of 14,746 residents, according to court papers.

Leonard Gorman, executive director of the Navajo Nation's Human Rights Commission, said he has attended several county commission meetings to urge redistricting but sees no indication that commissioners want to redraw the boundaries.

"What I understand is that every citizen in the union would be balanced. One man, one vote. That is a guarantee that is iterated in the U.S. Constitution," Gorman said in a telephone interview Thursday. "That is not being made available to citizens in San Juan County."

The county and commissioners Bruce Adams, Phil Lyman and Kenneth Maryboy are named as defendants in the lawsuit, along with Norman L. Johnson, the county's clerk/auditor.