A recent visit to northeast Ohio put me face to face with people involved in the production of shale gas that I've been hearing and reading about in the news.

It is one of the hot spots for sales of vocational trucks and trailers, and is boosting business in a region that's been hurting for jobs since the steel mills closed in the 1970s.

Rob Sidley, one of the family members running the Sidley Companies at Thompson, Ohio, was talking about the booming demand for "fracking" sand. Sand, water and chemicals are pumped into shale-rock formations deep underground to fracture the rock and free natural gas that's trapped there.

The Sidleys happen to both mine it on their sprawling property and haul it to drilling sites in pneumatic tankers - "air cans," Rob called 'em.

"We've got 20 trucks on, hauling sand, and we're about to put another 30 on," he said, still somewhat amazed at the fast growth of this business. "They can't get enough of it." Sidley Trucking uses 6,500-cubic-foot Heil tankers and Mack tractors to move the sand.

Oh - the Sidleys are also a long-time Mack dealership, so that's another way they're benefitting from the natural gas boom.

You've probably heard that the Marcellus Shale formation in eastern Ohio and western Pennsylvania contain trillions of cubic feet of natural gas. Some experts think that this gas, and other gas and oil deposits out West, will help the United States become largely self-sufficient in energy in the near future.

Fracking is controversial because it uses tremendous amounts of fresh water, and the chemicals in it are suspected of damaging drinking water close to the surface. Also, what goes down must come back up, and millions of gallons of brine must be stored, treated and disposed of.

Coal mining in bygone, unregulated times was grossly unkind to this region, and environmentalists don't want a repeat of that.

Rob and his associates say the danger is greatly overblown, with only a handful of operations causing problems among hundreds of thousands of other wells drilled over the years. Here in Ohio, the energy industry is running TV ads explaining how responsible drillers are careful to insulate well bores from surrounding earth, and how the activity creates jobs - a magic word in these times.

Sand seems to be a comparatively pure ingredient and is seldom mentioned in news-media stories. But it's important to the process. As the shale rock is fractured, the grains of sand act as tiny pillars, keeping the minute passages open so gas can escape and move to the surface.

The Sidleys have the sand and the tractor-trailers to carry it, and it seems they'll be plenty busy in coming years in this vital endeavor.