Yolanda Fraser is back near a ragged chain-link fence, blinking through tears as she tidies up flowers and ribbons and a pinwheel twirls in the breeze at a makeshift roadside memorial in a small Montana town.

This is where the badly decomposed body of her granddaughter Kaysera Stops Pretty Places was found a few days after the 18-year-old went missing from a Native American reservation border town.

Four years later, there are still no answers about how the Native American teenager was killed. No named suspects. No arrests.

Fraser’s grief is a common tale among Native Americans whose loved ones went missing, and she’s turned her fight for justice into a leading role with other families working to highlight missing and slain Indigenous peoples’ cases across the U.S. Despite some early success from a new U.S. government program aimed at the problem, most cases remain unsolved and federal officials have closed more than 300 potential cases due to jurisdictional conflicts and other issues.