Analysis of information sources in references of the Wikipedia article "Dances with Wolves" in English language version.
Although an 8 Jan 1989 LAT brief reported that principal photography would begin in Mexico in Mar 1989, filming did not take place in Mexico and the start date was pushed back to 17 or 18 Jul 1989, as noted in various sources including production notes in AMPAS library files, the 7 Jun 1989 HR and DV, and the 7 Jul 1989 HR.
17 or 18 Jul--21 or 23 Nov 1989
Although an 8 Jan 1989 LAT brief reported that principal photography would begin in Mexico in Mar 1989, filming did not take place in Mexico and the start date was pushed back to 17 or 18 Jul 1989, as noted in various sources including production notes in AMPAS library files, the 7 Jun 1989 HR and DV, and the 7 Jul 1989 HR.