"We do not inherit the Earth from our ancestors: we borrow it from our children."

This quote, along with some close variants, is sometimes labeled as an Indian proverb, or attributed to Antoine de St. Exupery, or to Ralph Waldo Emerson or to David Bower. Like Chief Seattle's famous environmental speech from 1854 (which was actually written by a screenwriter in 1971),the quote strikes me as a late-20th century idealization of what some revered figure in the past must have thought, supposedly.

Does anyone know the actual origin of this quote? Does it appear in any reliable collection of famous quotes?