The Arizona Department of Transportation is warning drivers in southern Arizona that pedestrians may be on the roadways.

These pedestrians are pilgrims, possibly crossing State Route 86 in the days leading up to Oct. 4. This is the Tohono O’odham's yearly religious pilgrimage to the church in Magdalena, Mexico.

The Tohono O’odham make the journey to be at Magdalena, Sonora, Mexico, on Oct. 4, St. Francis' Day. They go to kiss the head of the the St. Francis statue, according to research from the ASU School of Social Work.

Magdalena will host Tohono O'odham, Mexicans and other groups who each celebrate St. Francis' Day.

The Tohono O’odham have Christian and traditional beliefs, and call St. Francis Xavier their patron saint.

Hundreds of tribal members participate every year.

Magdalena is 120 miles south of Tucson. Many pilgrims leave from Sells, Arizona, and cross the border. The journey takes about a week, according to an interview with artist Allison Francisco in Southwest Folklife Alliance.

"The Walk" is full of meaning to the Tohono O’odham. It signals renewal, sacrifice and devotion to their beliefs.

Allison Francisco describes the milestones on each year of the pilgrimage. People carry staffs that identify them as pilgrims. Blessed ribbons can be tied to a pilgrim's staff. The more ribbons, the more years a person has taken the pilgrimage.

READ: Border wall may face Arizona hurdle from Tohono O'odham