Many long nights were spent filming the siege scenes. Loudspeakers were installed around the battlefield and fort so directions could easily be given to the hundreds of cast and crew. One night after many long hours, Mann shouted over the speakers, "What's that orange light? Turn out that orange light!" After a pause, another voice came over the speakers saying, "That's the SUN, Michael."
Wes Studi claimed in a 1996 interview that he and several of the other Native American actors spoke their lines in their own native languages. When Magua argues with the Huron Sachem in the Huron village, Studi speaks his native Cherokee, which is mostly unintelligible to Mike Phillips, a native Mohawk speaker. When Chingachgook talks with his son Uncas, Russell Means speaks Lakota Sioux to Inuit Eric Schweig.
By most accounts, each scene took at least 20 takes. Concerned about the growing cost, 20th Century Fox sent a representative to the set who did nothing but stand behind Michael Mann and say, "That's enough Michael, move on."
Daniel Day-Lewis is well known for going to extremes in preparation for his roles. For this film he lived in the wilderness where his character might have lived, hunting and fishing and living off the land for several months prior to shooting.
The shoot employed more than 900 Native Americans from all over the United States, mostly from the Cherokee nation.