BURNS, Ore. — A look at what led up to Tuesday's traffic stop, arrests and gunfire in eastern Oregon.

WHO IS INVOLVED?

An armed group took over a national wildlife preserve in southeastern Oregon more than three weeks ago. The group led by Ammon Bundy is upset over federal land policy. Before Tuesday's traffic stop, members have been free to come and go as they please. They've held frequent news conferences at the site, travelled to meet with sympathizers and others to espouse their views and some even attended a community meeting last week, where local residents shouted at them to leave. Frustrated local and state officials had urged the FBI to do something to resolve the situation.

HOW DID THIS BEGIN?

The group took over the Malheur National Wildlife Refuge on Jan. 2 after a peaceful protest in nearby Burns, Oregon, over the conviction of two local ranchers on arson charges. Dwight Hammond, 73, and his son Steven Hammond, 46, said they lit fires on federal land in 2001 and 2006 to reduce the growth of invasive plants and protect their property from wildfires. The two were convicted three years ago and served time — the father three months, the son one year. But in October, a federal judge in Oregon ruled their terms were too short under U.S. law and ordered them back to prison for about four years each. Among the demands by the Bundy group is for the Hammonds to be released.

IS THIS JUST ABOUT THE RANCHERS?

No. While Bundy and his group call for the ranchers to be released from prison the Hammonds have distanced themselves from the armed group. Increasingly Bundy has called for federal lands to be turned over to local authorities and has urged ranchers to renounce their federal grazing contracts. Bundy has said they plan to open the 300-square mile Oregon refuge to cattle this spring. Bundy and his family have for years said federal land management policies are harming ranchers and other locals in the West. Bundy is the son of Cliven Bundy, a Nevada rancher who in 2014 was at the center of a tense standoff with federal officials over cattle grazing rights.

ARE PEOPLE LISTENING TO THE BUNDYS?

While some local residents say the Bundy group is highlighting problems with federal oversight of local lands, the group has had very few people take the actions they've sought - specifically ranchers ripping up their federal grazing contracts. At an event the Bundy group staged at the refuge only one rancher - from New Mexico - renounced his agreement with the U.S. Forest Service to allow cattle grazing on federal land. The Oregonian newspaper reported that eight ranchers in Utah also said they would no longer allow federal officials to manage their grazing permits, but their attorney, Todd MacFarlane, didn't identify them. At a community meeting in Burns last week - attended by Bundy - some residents complained the armed group had disrupted the area and chanted loudly that they needed to leave Oregon.

CRITICS ASKED FEDERAL OFFICIALS TO STEP UP PRESSURE

Oregon Gov. Kate Brown and local leaders in Burns had urged the FBI to take action. The Burns Paiute Tribe also wanted federal officials to bar armed activists from traveling back and forth from the wildlife preserve, fearing tribal artifacts will go missing or the group will disturb burial grounds. Bundy's group took over buildings at the refuge that store over 4,000 archaeological artifacts and maps detailing where more items can be found. The tribe has "grave concerns regarding the present handling of the occupation as well as the prosecution of the militants," tribal chairwoman Charlotte Rodrique wrote in a letter Friday to U.S. Attorney General Loretta Lynch and FBI Director James Comey.