MORGANTOWN, W.Va. -- Thirteen activists demanding the end of mountaintop removal mining in Appalachia staged a nearly four-hour sit-in at Environmental Protection Agency headquarters in Washington, D.C., but left the building without incident yesterday.

Some 75 activists with Mountain Justice, Rainforest Action Network and other groups rallied outside that building while others held protests across the country, from California to Maine. Their targets included regional EPA offices and JPMorgan & Chase Co., a bank environmentalists say is the biggest financier of the destructive form of strip mining.

The Washington sit-in began about 11:30 a.m. and ended after police indicated they were prepared to make arrests.

"We didn't want them to spend the weekend in jail, so we sent people in and they agreed that they proved their point, and they left voluntarily," said Chuck Nelson, a disabled underground coal miner from Glen Daniel who said the protests had generated media coverage of the cause. "We accomplished what we came here for."

The protesters were disappointed they could not hand-deliver a letter to EPA Administrator Lisa Jackson, who was not in the building. Mr. Nelson said they ultimately delivered it to a staff member.

EPA spokeswoman Betsaida Alcantara issued a statement saying the agency respects the concerns and understands "the high emotions felt by many Americans."

Under Ms. Jackson's leadership, she said, EPA has worked with other federal agencies to take "unprecedented actions within the scope of the law ... to ensure the safety and health of mining communities."

It was the environmentalists' third attempt at a national protest since June, and evidence they believe the tide is turning in their favor under the Obama administration.

Chris Hamilton, vice president of the West Virginia Coal Association, was out of the office yesterday and did not immediately return a telephone message. Nor did Bill Caylor, president of the Kentucky Coal Association. Officials at JPMorgan & Chase Co. did not comment on being a planned target of the protests.

Mountaintop removal is a form of strip mining that blasts apart ridge tops to expose multiple coal seams. Operators level off the peaks, then dump rock and debris into valleys, often covering intermittent streams and changing the contour of the land.

Coal operators say it's often the most efficient and sometimes the only way to get to reserves, but many people who live near the mines say they suffer unacceptable damage to the environment and their homes.

Federal regulators are "starting to look at scientific evidence showing what filling in the streams and valleys does to our headwaters, to the whole ecosystem," Nelson said. "But we need to stress to the EPA that they need to make a decision soon because the longer this goes on, the more danger they're putting us in."

The EPA recently revoked a permit for what could have been West Virginia's largest mountaintop removal operation, citing "very serious concerns" about possible Clean Water Act violations. It was the first time since 1972 the agency had used its authority to review a previously permitted project.

Looking for more from the Post-Gazette? Join PG+, our members-only web site. You'll get exclusive sports content, opinion, financial information, discounts from retailers and restaurants, and more. Our introduction to PG+ gives you all the details.