WINDOW ROCK, AZ - On Wednesday, May 31, the Navajo Nation Museum in Window Rock, Arizona will host the first lecture in a series commemorating the 1868 Treaty between the Diné (Navajo) people and the United States. The event begins at 10:30 am and features Mark Charles, internationally renowned Navajo presenter who will speak on a seldom heard policy and the contributors that made Hwéeldi, the Navajo Long Walk possible.