This is the fourth largest collection of Mexican masks in the United States; this collection was assembled by William J. Breitenbach between 1968 -2004. The masks, which represent human faces, animal faces, or skulls are constructed of wood, ceramic, paper mache or leather. Most are brightly painted in a polychrome technique, some with incredibly detailed designs. Many are enhanced with quills, fur, hair, teeth, fabric, or wool.

These masks were used in festivals such as:

• Cinco de Mayo
  
• Semana Santa (Holy Week)
  
• Los Dias de los Muertos (Day of the Dead)
• Danza de Moros e Cristianos (Dance of the Moors and Christians)
  
• Danza el Borrgo Cimarron (Dance of the Wild Sheep)
• Danza de Parachicos (Dance of the Parachicos)
  
• Danza de Tigres (Dance of the Jaguars)
  
• Carnival de Huejotzingo (Carnival of Huejotzingo)
  

Breintenbach travelled throughtout the nation of Mexico. He bought masks from well known mask maskers, undiscovered artists, and apprentices, giving his collection great variety.

Mexican states represented in the collection include:

• Chiapas
• Guanajuato
• Guerrero
• Mexico
• Michoacan
• Morelos
• Oaxaca
• Puebla
• Querterero
• Tlaxcala
• Vera Cruz