National Guard helicopters are scooping up the stranded while hundreds more are being driven to safety in convoys. As of this morning, the Guard had evacuated nearly 800 people by air and ground.
Two towns east of Greeley were being evacuated today. The towns of Goodrich and Orchard are close to three large reservoirs.
Meanwhile, authorities in Larimer County say a woman is missing and presumed dead after witnesses saw floodwaters from the Big Thompson River destroy her home in the Cedar Cove area.
Four people have been confirmed dead since the floods began Wednesday, but authorities say that number is likely to grow.
More than 170 people remain unaccounted for in Boulder County, but the sheriff says that number could include people who are still stranded or who escaped but have not yet contacted anyone.