On the third Saturday of each month, out in the fields of Hockley's Zube Park, the Houston Area Live Steamers come out to play.

The steamers are a group of more than 80 local railroad aficionados who build model trains, many of which are big enough to ride. Since working out a deal with Harris County to lay track around the park, HALS has laid down more than 5,000 feet, including a 4,700-foot outer loop for public rides.

"It started out with just a few individuals who had track going around their houses," said Dennis Cranston, who has been with HALS for more than 20 years. "They wanted something bigger, something they could share with others."

HALS offers free train rides on its public run days, where anywhere between 800 to 1,600 people might show up. Although model train building is a fairly widespread hobby throughout Texas, Cranston said the Zube Park track is one of the only places in the state that is open to the public.

"You don't hear about [model trains] because most people just do it privately," he said. "The volunteers here like working with people. A lot of us are at the grandfather level. We like seeing the smiles on the kids' faces."

The group has completed three separate phases of track and is working on a phase four, which will be completed within the next few years.

"It's going to involve a big bridge that's going to be a signature effect of the park," he said. "Each phase brings more to the overall experience."

Houston Area Live Steamers, Zube Park, 17400 Roberts Road, Hockley, www.hals.org