Parkhurst was also a member of the Maine Militia, serving as Commissary General with the rank of colonel from 1901 to 1904.

In 1920, he defeated incumbent Carl Milliken in Maine's Republican primary for governor.

Parkhurst managed to leave his sickbed to take the oath of office, but died of pneumonia just three weeks later.

His 26 days as Governor make his term one of the shortest in Maine history; the record belongs to Nathaniel Haskell, who served for 25 hours in 1953.

Senate President Percival Proctor Baxter, also a Republican, finished Parkhurst's term in office.