Arizona homebuilder spent years and thousands of dollars building a 4,000-foot backyard railway

Arizona businessman Dennis Sirrine spent years and hundreds of thousands of dollars transforming his backyard into one of America's largest private garden railways.

Started in 2004, the Palo Verde & Southwestern Railroad featured nearly 4,000 feet of track, hundreds of model train cars, artificial mountains and lakes.

The project involved extensive construction, repeated rebuilding and a specially designed operating system.