Watch the Indigenous Water Ceremony That Opened the People's Climate March in Washington, D.C.

As President Trump marked his 100th day in office on Saturday, up to 200,000 people took to the streets of Washington to take part in the People's Climate March. Sister marches were also held across the country. The protesters decried President Trump's steps to roll back environmental regulations, appoint climate change deniers as the heads of government agencies, and defund and erase climate change programs and research, including the administration's move Friday to scrub climate science pages from the EPA's website. The People's Climate March began at dawn on Saturday with a water ceremony led by indigenous peoples at the Capitol Reflecting Pool.