Erin Reinders is officially Unalaska's city manager.
She took her oath of office at Tuesday's City Council meeting.
"I'm happy to be here," she said. "And I'm hitting the ground running."
Reinders has worked for the city since 2011 and started serving as assistant city manager in 2015.
Mayor Frank Kelty welcomed Reinders to her new post as he wrapped up Tuesday's meeting, where she received a standing ovation.
"Council directives to the city manager? The only directive is: Congratulations, best of luck, and hope we don't turn your hair gray," said Kelty.
Meanwhile, Thomas did not state a reason for his resignation or respond to multiple requests for comment before leaving the island.