Hundreds gathered in front of the White House on Oct. 11 to protest the use of fossil fuels. (Video: The Washington Post, Photo: Eric Lee/The Washington Post)

Casey Camp-Horinek, a tribal elder from White Eagle, Okla., and environmental ambassador for the Ponca Nation, marched in the front of a crowd of hundreds headed toward the White House on Monday and held up her fist.

The 73-year-old — wearing a hat that said “Pipeline Fighter” — was among the leaders and members of Native American tribes from across the country who came to Washington for five days of protests that began Monday.