Viewers who called into the Denver7 newsroom said crowds were big enough to take up four blocks before anyone could reach Civic Center Park.
The hundreds of thousands of people gathered at Civic Center Park caused communication issues. Denver7's Amanda del Castillo said many, including the Denver7 field crew, were unable to complete calls, send texts, or post to social media.
While nearly 100,000 people participated in the march through downtown Denver, hundreds of others stayed behind at Civic Center Park and even lined steps at the State Capitol.
12:03 p.m. - There are approximately 100,000 participants at Women's March on Denver, according to Lisa Cutter, a March on Colorado spokesperson. The number could swell up to 200,000 by the afternoon.
12:17 p.m. - So far, three people have been arrested: One person had an active warrant, another was arrested for an assault to a police officer and a third was in possession of an illegal weapon, according to a spokesperson from the Denver Police Department.
The Women's March Denver is expected to go through the rest of the morning into late Saturday afternoon.
Watch the crowds march in Denver as seen from AIRTRACKER7 below: