On the northwest corner of North Stone Avenue and Franklin Street, just south of the railroad tracks, rests the foundation of what looks like a long-lost building.

On the east edge of the foundation, which sits next to a downtown parking lot crisscrossed with buried railroad racks, are two staircases. One has the year "1930" written near it.

The structure that sat on the foundation - the Southern Pacific Freight Depot - was razed decades ago and played an important part in Tucson's rail history.

When the Southern Pacific Railroad chugged into town in 1881, it transformed the face of the Old Pueblo, says a Historical Survey of Downtown Tucson, Az., prepared in 1984.

"No longer was the homeowner a merchant of modest means, limited to bare necessities hauled by mule and wagon or laboriously fashioned by hand," the survey says. "Suddenly milled lumber and tin for roofs, wallpaper and lace for interiors, and even fine china dishes were within the reach of thrifty Tucsonians."

The freight depot, a block-long row of warehouses between Stone and Church avenues, played a significant role in the distribution of these goods, the survey says. It was built in 1906 and served as the railroad's main shipping facility for many years.

"In 1930, a handsome, two-story office addition was constructed at the east end, fronting on Stone Avenue (six years before the underpass was built)," the survey says.

The building was one of Southern Pacific's oldest structures, lending it regional and local significance, the survey concludes.

Contact reporter Dale Quinn at dquinn@azstarnet.com or 573-4197.