Tension over the drought-stressed Colorado River escalated into a public feud when four U.S. states accused Arizona's largest water provider of manipulating supply and demand, potentially threatening millions of people in the United States and Mexico who rely on the river.

All along the U.S.-Mexico border, about 840,000 mostly low-income, immigrant Latinos have settled in colonias – cheap plots of land outside city limits without basic infrastructure such as water and sewage systems, electricity and paved roads.

As President Donald Trump tries to persuade a skeptical Congress to fund his proposed multibillion-dollar wall on the Mexican border, government lawyers are still settling claims with Texas landowners over a border fence approved more than a decade ago. Two settlements were completed just this week.

Electricity-generation markets across the U.S. are changing, which is to say they are modernizing. Our research shows time and again that coal-fired generation plants are no longer the viable business propositions they used to be.

Republicans say they're not satisfied with a U.S. Environmental Protection Agency claim that a 3-million-gallon toxic spill from an inactive gold mine was likely "inevitable," even though there had been prior warnings that such a spill could occur.

Citing the release of millions of gallons of toxic wastewater into a southwestern Colorado river earlier this month, a coalition of conservation groups, two Arizona Native American tribes and two county governments petitioned federal agencies Tuesday to tighten mining regulation on public lands.

Authorities say rivers tainted by last week's massive spill from an abandoned Colorado gold mine are starting to recover, but for the Environmental Protection Agency the political fallout from the disaster could linger.

Arizona officials continue to monitor a massive spill of toxic sludge that is heading toward the Colorado River, but most were hopeful Tuesday that it will have little impact by time it reaches the state.

Local officials in towns downstream from where millions of gallons of mine waste spilled into a southwest Colorado river are demanding answers about possible long-term threats to the water supply.

The U.S. government will invest nearly $50 million in water conservation and reuse projects in 12 drought-stricken Western states, Interior Secretary Sally Jewell announced Wednesday.