Stations across the state are profiling notable highway markers in the On the Road in Arizona series. The four-part series is a collaboration between public radio stations KJZZ, AZPM, KAWC and KNAU.

Ancient farmers dug canals that shaped Phoenix's modern water system

Just south of the intersection of North Horne and East McKellips Road in Mesa sits the Park of the Canals. It’s one of just a few places where you can still see remnants of canals dug by the ancestral Sonoran Desert people who occupied the Salt River Valley before the time of Christ.

Historical marker shows where Hollywood legend met his end

Before there was Clint Eastwood, before Roy Rogers, even before John Wayne, there was Tom Mix. Learn about the historical marker that commemorates the road where his life came to an end.

When 2 planes collided over the Grand Canyon in 1956, it changed aviation forever

Before there was a United States Border Patrol, the customs service was the first line of defense along the U.S.-Mexico border. Their headquarters — now designated by a historical marker — still stands.

This historic Yuma site was used to store drugs seized at U.S.-Mexico border

For years, it served as an Army hub, where shipments came and went via mule-drawn wagons and even steamboats on the Colorado River. The facility was later used to store drugs and other contraband seized at the U.S.-Mexico border.