[1] Riordan was once the site of a train depot, lumber mills, a bunkhouse, post office, school, and store, but little remains today.

Riordan was located on the Atchison, Topeka and Santa Fe Railway (AT&SF) approximately 6.5 miles (10.5 km) west of Flagstaff, Arizona.

[7] The Santa Fe Railway constructed a depot, bunkhouse, and several dwellings; the logging company established a store.

[3] At that time, the Flagstaff Coconino Sun stated that "Riordan is rapidly growing into a thriving little city".

[3] By the late 1960s, the community had fallen into ruin, with the Phoenix Arizona Republic reporting that there was little left at the site in 1969.