(Reuters) - U.S. President Donald Trump on Tuesday pardoned two imprisoned Oregon ranchers whose sentencing on arson convictions sparked the 2016 occupation of a wildlife refuge, part of a long-simmering dispute over federal land policies in the U.S. West.

The armed standoff at the Malheur National Wildlife Refuge in southeast Oregon followed a judge’s ruling that sent Dwight Hammond and his son, Steven, back to prison to serve more time after their initial release. Police shot one of the occupiers dead during the 41-day midwinter protest.

The takeover was another flare-up in a decades-old conflict over federal control of millions of acres of public land in the Western United States. In Oregon, about half of all land is controlled by the federal government.

The leaders of the Malheur standoff, including activists Ammon and Ryan Bundy, were cleared of federal charges for their role in the protest in October 2016.

Ammon Bundy on Tuesday called the pardon “long overdue.”

“We went up there to prevent the atrocity from happening to begin with, and if people would have listened to us, the Hammonds wouldn’t have to have gone through this suffering,” Bundy said in a telephone interview.

The pardons are the latest in a series by Trump that have raised questions about whether he is using the presidential power to reward political supporters.

Trump in late May pardoned Dinesh D’Souza, a conservative pundit convicted of campaign finance crimes. Last August he pardoned former Arizona sheriff Joe Arpaio, who campaigned for Trump before being convicted in a case regarding racial profiling.

“LAWLESS EXTREMISTS”

A U.S. flag covers a sign at the entrance of the Malheur National Wildlife Refuge near Burns, Oregon, January 3, 2016. REUTERS/Jim Urquhart

Dwight Hammond, 76, and Steven, 49, were convicted in 2012 for setting a fire that spread onto public land after years of disputes with the U.S. Bureau of Land Management.

The Hammonds said they were using standard brush-control and land-management techniques, but the government said that in at least one instance they were trying to hide evidence of their slaughtering a herd of deer.

The Hammonds were set to return by airplane to Oregon on Wednesday morning, the Bundy family said in an email. The pair walked out of a federal prison in California about 6-1/2 hours after the pardon was announced, the Oregonian newspaper reported.

Some conservation groups were dismayed at the pardon.

Jennifer Rokala, executive director of the Center for Western Priorities, called the Hammonds “lawless extremists.”

“Pardoning the Hammonds sends a dangerous message to America’s park rangers, wildland firefighters, law enforcement officers, and public lands managers,” Rokala said in a statement.

The two men were initially sentenced to less than the legal minimum five-year prison sentence by a judge who thought the minimum too harsh and later released the two, Dwight Hammond after three months and Steven Hammond after a year.

After the government’s appeal in 2016, a different federal judge ordered the pair back to prison to serve the full five years, sparking protests and the refuge occupation.

In a statement on Tuesday, the White House said the decision sentencing the Hammonds to five years in prison was “unjust” and said that the fire had burned only “a small portion” of public land.

“The evidence at trial regarding the Hammonds’ responsibility for the fire was conflicting, and the jury acquitted them on most of the charges,” the statement said.

As of 2018, Dwight Hammond had served about three years in prison and Steven Hammond had served four, according to the White House.