O.B. Huntington recorded in his journal the following observation by Joseph Smith:[footnote]Prophet Joseph Smith, Jr., in Journal of O.B. Huntington, Book 14, p. 166[/footnote]

Inhabitants of the Moon are more of a uniform size than the inhabitants of the Earth, being about 6 feet in height. They dress very much like the Quaker Style & are quite general in Style, or the one fashion of dress. They live to be very old; comeing [sic] generally, near a thousand years.’ This is the description of them as given by Joseph the Seer, and he could ‘See’ whatever he asked the Father in the name of Jesus to see.

Later in 1892, an LDS article entitled “The Inhabitants of the Moon,” recorded Huntington:[footnote]The Young Women’s Journal 3:263[/footnote]

“As far back as 1837, I know that he [Smith] said the moon was inhabited by men and women the same as this earth, and that they live to a greater age than we do—that they live generally to near the age of a 1000 years. He described the men as averaging near six feet in height, and dressing quite uniformly in something near the Quaker style”

Crash Course:

Joseph Smith’s Moon Men – Mormon Musings
Did Joseph Fielding Smith prophesy that men would never walk on the moon? – Fair Mormon