The U.S. Department of Interior is investigating whether mining companies are skirting royalty rules as they increase exports of coal to Asia, federal officials disclosed Friday.

Proponents say a single, smaller tunnel coupled with investments such as water recycling and desalination would result in more water for cities and farms. They say it also would be better for the environment and cost less — with construction...

Stepping into his second term, President Barack Obama took the oath of office Sunday in an intimate swearing-in ceremony at the White House.

Interior Secretary Ken Salazar, who oversaw a moratorium on offshore drilling after the BP oil spill and promoted alternative energy sources throughout the nation, will step down in March.

A Kansas battlefield where forces faced off over slavery several years before the Civil War, two New England churches, and several sites associated with indigenous North American cultures are among 27 places designated new National Historic...

The government is establishing 17 new "solar energy zones" on 285,000 acres in six states: California, Nevada, Arizona, Utah, Colorado and New Mexico. Most of the land — 153,627 acres — is in Southern California.

President Barack Obama on Monday designated the home of Latino labor leader Cesar Chavez as a national monument, calling Chavez a hero who brought hope to millions of poor, disenfranchised farm workers who otherwise might have remained "invisible" to much of the nation.

LAS VEGAS (AP) — The politics of renewable energy headed the agenda in battleground Nevada, where Democratic Senate Majority Leader Harry Reid and Interior Secretary Ken Salazar opened a fifth annual green energy conference touting the start of a...