Simplify the following text for a Grade 6 native English-speaking person.
Original: The upper reaches of the Macquarie River were first sighted by Europeans in 1813 and the river was named for the then Governor of New South Wales , Lachlan Macquarie .
Simplified: The upper parts of the Macquarie River were first seen by Europeans in 1813 . The river was named for the Governor of New South Wales , Lachlan Macquarie .