According to Politico, the small plane crashed near a small fishing town on Alaska's Bristol Bay.
"The family has just been notified that he did not survive," said Mitch Rose, former chief of staff for Stevens who served 41 years in the Senate before being convicted on corruption charges and losing his seat in 2008. The charges were later dismissed because of prosecutorial misconduct.
Nine people were aboard the private plane, a De Havilland DHC-3T Otter owned by telecom company GCI.
The National Transportation Safety Board has dispatched investigators from Anchorage and Washington, D.C. Board chairman Deborah AP Hersman is accompanying the team and will serve as spokesperson for the on-scene investigation, the agency said in a statement.