As executive vice president of the Ohio Oil and Gas Association, Thomas Stewart has had a front-row seat -- but never an invitation -- to the natural gas party happening in Appalachia's Marcellus Shale.

"Up until now, we've all just been watching what a wonderful time you're all having in Pennsylvania," he said.

That "until now" clarification comes courtesy of the oil and gas in a different black rock underlying major portions of the Buckeye State.

The Utica Shale, another relic from the primordial era, is deeper and thicker than its Marcellus counterpart; but enthusiasm for its reserves already has energy executives and landowners staking a claim and making sure another trillion-dollar opportunity doesn't pass them by.

Two major drillers, Chesapeake Energy of Oklahoma City and Consol Energy of Cecil, recently announced exploratory plans for the Utica Shale, evoking a sense of deja vu from the early, quieter days of Marcellus development.

Attention so far has fixed on Ohio and the Utica's oil-rich regions, but gas found in the Utica below southwestern Pennsylvania and northwestern West Virginia are considered "very worthwhile," said Nick DeIuliis, president of Consol Energy.

Under a joint venture with New York-based Hess Energy, Consol initially will focus on the "dry gas" portions of the Utica Shale, where extracted gas doesn't come with additional compounds like ethane attached. Hess plans to operate in the liquid-heavy zones of Consol's 197,000 Utica acres, said Mr. DeIuliis.

The deal between the two companies was worth $593 million -- a bargain in the regional shale industry, which has become accustomed to dealing in billions of dollars.

Mr. DeIuliis credits the recent interest in the Utica Shale to a combination of price points: The land is still unexplored and therefore cheaper than Marcellus acreage, and the price of oil is hitting record levels.

Oil is currently trading at nearly $100 per barrel, so it's "not a shock" that the Utica has sparked interest, said Mr. DeIuliis. Consol is counting on the tapping of the resources there being a "30- to 40-year opportunity for our shareholders."

There's a lot of acreage still left: The Utica covers a larger swath of land than the Appalachia-centered Marcellus, heading as far south as Tennessee and as far north as Canada.

In parts of southwestern Pennsylvania, about 5,000 feet separate the two formations. In Ohio, they're closer together, with between 2,000 and 3,000 feet of other formations separating them. Both proximities would allow companies to "double-dip" into both formations from the same well site.

Companies would most likely drill in the Utica first and then work up to the Marcellus, said Robert Ryder, a petroleum geologist with the U.S. Geological Survey in Reston, Va.

The Utica is nearly 100 million years older than the 350 million-year-old Marcellus Shale, and reaches depths of nearly 2.5 miles. It also tends to be thicker than the Marcellus rock, topping out at nearly 900 feet, or about as thick as the Trump Tower in New York City is tall.

The 450 million-year-old rock now getting its 15 minutes of fame started as an ocean floor resting beneath a shallow pool of water, said Mr. Ryder. "It was a place that allows a lot of organic material to live, and more and more sediment gets piled on top."

The rock contains hardened zoo plankton, smaller plants and microscopic organisms -- all fossilized remains that turn into Texas tea if given 450 million years.

The Utica Shale's closer proximity to the heat of the Earth's core allowed oil to develop. The Marcellus Shale has "the ingredients to form oil," said Mr. Ryder, but geologists haven't found any substantial amount.

And while domestic enthusiasm for the Utica Shale has focused on its oil reserves, energy firms have already extracted natural gas from Utica drilling sites in Quebec using the hydraulic fracturing technology that splinters rock and allows natural gas to escape.

Wall Street interest took off in late July, when Chesapeake Energy CEO Aubrey McClendon announced to shareholders that his company had quietly accrued 1.25 million acres of land in the Utica Shale that it believed to be worth between $15 billion and $20 billion. The company raised its drilling budget by $500 million to $6.5 billion this year, in part to account for the Utica development.

Mr. McClendon even went on CNBC's "Mad Money" show to talk up the discovery with host Jim Cramer, positioning himself and his company as the first Utica stakeholders.

Consol Energy soon followed, causing industry watchers to draw parallels to when exploration in the Marcellus Shale was in its infancy.

"Marcellus is a young adolescent that's coming of age and, so far, so good," said Mr. DeIuliis. "The Utica is just a toddler ... ; it feels so much like the Marcellus did three years ago."

The Utica Shale didn't catch anyone by surprise -- experts have been aware of it for a while -- but successful use of the hydraulic fracturing technology in the Marcellus Shale led companies to eye the other play.

"It played out at the rate everyone anticipated," said Mr. DeIuliis.

Landowners across Pennsylvania have already hedged their bets on using the Utica Shale for a second payday, said John Smith, an attorney at Smith Butz LLC in Southpointe.

"On the leasing front, we separate Utica from Marcellus," he said. That gives landowners the chance to sign two leases on the separate shales underneath the same property.

"It's just like leasing new ground," he said. "You could conceivably have a number of different companies leasing different layers of ground."

Mr. Stewart, of the Ohio industry group, praised his state's lawmakers as welcoming to the industry and said some of the drilling growing pains -- namely, community outcry over the controversial fracking technique -- might be mitigated by the region's history with extraction.

"All of Eastern Ohio is very used to seeing oil and gas development, and seeing drilling and completion operations," he said. "That's a yawner for them."

What has become a subject of debate is whether to tax the industry, with many proponents seeing a driller tax as a possible antidote to the budget shortfalls facing small communities across Ohio.

Mr. Stewart's organization has also seen increased interest from shale cottage industries, such as industry consultants, law firms and environmental groups.

But the on-the-ground side effects like crowded restaurants or overbooked hotels haven't hit just yet.

"It'll accrue at a more moderate pace than what happened in Pennsylvania, in a more -- what's the word? -- rational way," he said.