ORANGE — After nearly eight years on the job, Superintendent Tari Thomas has announced her retirement.

In a letter sent to colleagues last week, Thomas, superintendent of the Orange Elementary Schools, Ralph C. Mahar Regional School and Petersham consolidated school districts, said she is entering her last year in education, and her retirement will be official in August 2020.

“It has been said that, when it is time to make the decision to retire, you will know it,” Thomas said. “For me, that time has arrived.”

Thomas has been superintendent of the three neighboring — and overlapping — districts since July 2011.

She is entering her 37th and final year as an educator, having started as a second grade teacher in rural Maine in the 1980s, then teaching in Lenox before becoming principal of Shutesbury Elementary School and then Clifford M. Granger School in Agawam.

“This is a bittersweet moment for me, as I am saddened to leave colleagues and friends, yet excited and optimistic about the next phase of my life,” Thomas said.