LaDuke is executive director of the Native American environmental group Honor the Earth. She said it's time for a new leader on White Earth.
"I have a lot of respect for any tribal leader," she said. "But if you think what we're doing is working, come here and look around. It's not."
The office is up for election in June 2016, but could open earlier.
LaDuke's bid comes in the wake of a power struggle that could cost current tribal Chair Erma Vizenor her job. The Minnesota Chippewa Tribe removed Vizenor from its governing board early last week, claiming she overstepped her authority in an attempt to replace the tribal Constitution.
The MCT governs six Minnesota bands, including White Earth, and is led by a board made up of tribal chairs and secretary-treasurers from each band. Vizenor still holds her office on White Earth, but removal from the MCT board leaves her job in the hands of the White Earth Tribal Council.
Meetings have not yet been scheduled, but the council will vote to either force Vizenor out, hold a recall election or take no action at all. In a previous interview Vizenor said she expects a recall election. That could open the field for LaDuke, months before the 2016 tribal election.
Running for tribal office marks a shift in priority for LaDuke. She was Ralph Nader's Green Party vice presidential candidate in 1996 and 2000, but formerly denied any interest in joining reservation politics.
Instead she focused on starting programs like the White Earth Land Recovery Project, Native Harvest and a tribal radio station. Staying out of tribal government gave her more time to protest Enbridge's proposed Sandpiper oil pipeline.
She's well known for riding on horseback across the state to protest the pipeline.
Her decision to run now, she said, is thanks to recent changes on the White Earth tribal Council.
In 2014 three former council members lost their seats to Tara Mason, Steven Clark and Kathy Goodwin.
"The council used to be very combative with me," LaDuke said. "Now I walk in there and I don't feel like I'm going to get yelled at. I can work with them."
With the mostly new council, LaDuke said she can do more good in government than on the outside. She plans to introduce programs to get tribal members out of the prison system, decriminalize marijuana and build up Ojibwe centered agriculture on the reservation.
"We let Walmart feed us," she said. "I want herds of buffalo on White Earth. I want gardens. I want to us to feed ourselves."
She also plans to work toward constitutional reform, and continue her efforts to block the Sandpiper oil pipeline.