1 of 26 Navajo man, half-length, seated, facing front, wearing a ceremonial mask with feathers and with fir or spruce branches forming a wreath around the shoulders, 1904. Edward Curtis/Library of Congress

2 of 26 Person wearing Mask of Tsunukwalahl, a mythical being, used during the Winter Dance, 1914. Edward Curtis/Library of Congress

3 of 26 Navajo man wearing mask of Ganaskidi, god of harvests, plenty, and of mists, 1905. Edward Curtis/Library of Congress

4 of 26 Koskimo person wearing full-body fur garment, oversized gloves and mask of Hami ("dangerous thing") during the numhlim ceremony, 1914. Edward Curtis/Library of Congress

5 of 26 Tonenili-Navajo, dressed in spruce branches, 1904-1905. Edward Curtis/Library of Congress

6 of 26 Kwakiutl person wearing a mask of the mythical creature Pgwis (man of the sea), 1914. Edward Curtis/Library of Congress

7 of 26 Navajo man wearing leather mask with basket cap, fur ruff, nude torso painted with white lines, 1904-1905. Edward Curtis/Library of Congress

8 of 26 Ceremonial mask worn by a dancer portraying the hunter in Bella Bella mythology who killed the giant man-eating octopus. The dance was performed during Tluwulahu, a four-day ceremony prior to the Winter Dance, 1914. Edward Curtis/Library of Congress

9 of 26 Navajo man wearing dark mask, fur ruff, paint on torso, 1904-1905. Edward Curtis/Library of Congress

10 of 26 A Navajo man, full-length, in ceremonial dress including mask and body paint, 1904. Edward Curtis/Library of Congress

11 of 26 Dancer wearing raven mask with coat of cormorant skins during the numhlin ceremony, 1914. Edward Curtis/Library of Congress

12 of 26 Dancer wearing oversize mask, three rings of feathers in front of clothing, holding a rattle, 1913. Edward Curtis/Library of Congress

13 of 26 Navajo man bedecked in hemlock boughs and mask of a clown associated with the mischievous rain god Tonenili, "Water Sprinkler," 1905. Edward Curtis/Library of Congress

14 of 26 Kwakiutl person wearing an oversize mask and hands representing a forest spirit, Nuhlimkilaka ("bringer of confusion"), 1914. Edward Curtis/Library of Congress

15 of 26 Man dressed in a full-body bear costume. The bear had the duty of guarding the dance house, 1914. Edward Curtis/Library of Congress

16 of 26 Navajo man wearing dark leather mask, fur ruff, cloth girdle, silver concho belt and necklaces, 1904-1905. Edward Curtis/Library of Congress

17 of 26 Dancer representing Paqusilahl ("man of the ground embodiment"), wearing a mask and shirt covered with hemlock boughs, representing paqus, a wild man of the woods, 1914. Edward Curtis/Library of Congress

18 of 26 Navajo man wearing mask of Haschebaad, a benevolent female deity, 1905. Edward Curtis/Library of Congress

19 of 26 During the winter ceremony, Kwakiutl dancers wearing masks and costumes crouch in foreground with others behind them. The chief on the far left holds a speaker's staff. Three totem poles in background, 1914. Edward Curtis/Library of Congress

20 of 26 Ceremonial dancer, full-length portrait, standing, wearing mask and a fur garments during the Winter Dance ceremony, 1914. Edward Curtis/Library of Congress

21 of 26 A ceremonial mask of Nunivak, 1929. Edward Curtis/Library of Congress

22 of 26 Person wearing ceremonial mask of the Nuhlimahla during the Winter Dance ceremony. These characters impersonated fools and were noted for their devotion to filth and disorder, 1914. Edward Curtis/Library of Congress

23 of 26 Woman wearing a fringed Chilkat blanket, a hamatsa neckring and mask representing deceased relative who had been a shaman, 1914. Edward Curtis/Library of Congress

24 of 26 Two Native American men in costumes wearing horns of buffaloes, 1927. Edward Curtis/Library of Congress

25 of 26 Sisiutl, one of the main dancers in the Winter Dance ceremonies, wearing a double-headed serpent mask and shirt made of hemlock boughs, 1914. Edward Curtis/Library of Congress