Flooding Sparks Evacuations in Montana, Washington, British Columbia (PHOTOS)

Melting snow from the higher elevations has caused big problems in several areas of the Northwest and up into Canada as winter weather ceased and a spring warm-up finally took hold, and the dangerous situation has forced thousands from their homes.

A state of emergency was declared for 20 counties in eastern Washington as water levels rose rapidly and forced some residents out of their homes. One of the affected rivers, the Okanogan, is projected to crest at its third-highest level on record by the weekend.

Near the central Washington town of Leavenworth, residents of about 50 homes were being told to prepare for evacuations as a nearly 100-year-old dam was threatened by rising water levels. Parts of the earthen portion of the dam had already given way, and officials were concerned about whether or not the rest of the dam would also become overwhelmed by the floodwaters, the Associated Press reported.

To the north, more than 4,000 people were ordered to evacuate in and around British Columbia's Fraser Valley because of a swollen river. River forecasters say the Fraser River will continue to rise in the coming days as more snow melts and flows downhill into the waterway.

More than 60 houses in the Orchard Homes neighborhood of Missoula, Montana, were ordered to evacuate as a river that flows through the city of 70,000 reached its second-highest level on record. The Clark Fork River has been receding for days thanks to colder temperatures, but it's expected to peak at an even higher level toward the end of this week.

We'll continue to update the gallery at the top of this page with the latest images from all three floods, so please check back frequently.