The Pleasanton-Tulancingo Sister City Association (PTSCA) was established in 1984 to promote a Sister-City relationship between Pleasanton, California and Tulancingo, Hidalgo, Mexico.

Since then, many mayors, board members, civic leaders, community and business people, and students have traveled back and forth as delegates and ambassadors of cultural learning and experience.

The exchanges have crossed all types of organization, from fire departments to high school, from orphanages to recycling centers, hospitals to bridges, monuments, libraries and city halls.