Here's a look at the latest developments in the Colorado mine spill. All times are local.

12:05 p.m.

Tribal officials with the Navajo Nation have declared an emergency as a massive plume of contaminated wastewater from an abandoned Colorado mine flows downstream toward Lake Powell, which supplies much of the water to the Southwest.

State environment officials in New Mexico and Utah say the plume is passing through the Navajo Nation and headed toward Montezuma Creek near the town of Bluff, a tourist destination.

Some drinking water systems on the Navajo Nation, which spans parts of New Mexico, Arizona and Utah, have shut down their intake systems and stopped diverting water from the San Juan River.

Drinking water is being hauled to some communities.

Navajo President Russell Begaye says the tribe is frustrated with U.S. Environmental Protection Agency and he plans to take legal action. An EPA supervised crew has been blamed for causing the spill while attempting to clean up the area.