These protesters in Washington, D.C., are on a mission to stop the Keystone XL pipeline.

The pipeline would connect Canada's oil sands region to refineries on the U.S. Gulf Coast.

Saturday's event ends a week of protests by the Cowboy and Indian Alliance.

(SOUNDBITE) (English) PROTESTER IRVING GAITHER SAYING:

"I think that we're going up against a lot of people who have a lot of money. What we have to do is we have to align so I like the idea that the cowboys and the Indians have a mutual problem and they are aligning together to talk about it and to get their voice out there."

The protesters say the pipeline will hurt the environment and worsen climate change.

President Barack Obama has said he will have the final say on whether to greenlight the project.

(SOUNDBITE) (English) PROTESTER VICKI RYDER SAYING:

"I've come to stand in support of our native peoples who are trying to keep the Earth safe and free from pollutants for our grandchil