Immigrant rights advocates wrapped up their 10th annual Migrant Trail walk.
It was a walk of remembrance for thousands of men, woman and children who have died trying to cross the border.
Nearly 60 hikers, traveled 75 miles from Sasabe, Sonora Mexico to Tucson.
"We were literally walking through this corridor where people are being funneled and pushed through the desert," said Marisol Flores-Aguirre, a Tucson native.
Participants traveled from all over the world.
"Emotionally you just felt all that energy of those people, those deaths that happened out there. And I think that was the most challenging part," said Alfredo Villages, a Tucson Local.
The migrant trail goes through the Altar Valley in the Sonora Desert. Advocates call it the most traveled route for migrants.
In fact, they say it's where the majority of human remains are recovered.
"When you see that you have no idea what happened to that person, you have know idea if what you are looking at is remains of that person," Flores-Aguirre.
Walkers say as they passed by signs of life and death, they carried crosses to remember the dead. Many of them with the words desconcido. A Spanish word that translates into 'unknown.'
"Somewhere out there, there's a mother, there's a father, there's a family member that's never going to know what happened to their loved ones," said, Flores-Aguirre.