La Acequia del Rito y la Sierra in the Mora Valley is the highest and most famous traditional irrigation system in New Mexico. When children ask, some parents attribute the task of moving mountains and changing the course of rivers to Juan del Oso, the stouthearted man whose father was a bear. In this children's tale, agriculturalist Juan Estevan Arellano and folklorist Enrique Lamadrid share a unique version of a celebrated story that has been told in northern New Mexico for centuries.