But many of the heavy-duty pickups and the utility trucks with the Texas and Louisiana license plates are now heading down the road - some as far away as 80 miles - on a two-week hiatus.
They are making room for minivans carrying fans and families of Little Leaguers swarming into the city for the 10-day international tournament.
"That's our heritage," said Jason Fink, vice president of the Williamsport-Lycoming County Chamber of Commerce. "It's great to have a new industry, but we are the home of Little League baseball."
Little League has long been the biggest economic boost for Lycoming County and Williamsport, a city of 30,000 people on the West Branch of the Susquehanna River that in the late 19th century was known as the lumber capital of the world.
The World Series draws 70,000 visitors from around the world and generates $20 million for the local economy. (The city does have another source of income from baseball - it is the home of the Phillies' Rookie League team, the Crosscutters.)
Marcellus Shale, which runs underneath this central Pennsylvania region, has far greater potential than baseball to restoring Williamsport as an industrial hub.
Fink said it was too early to say how much the shale activity has contributed to the area's economy, but it has spurred commercial activity, bringing in restaurants and retailers.
Even with the money flowing in from drilling, it dawned on hotel operators last year that Little League and the gas industry would be on a collision course this summer because of the hotel commitments for baseball.
"We started hinting to guests that Little League was coming a few months ago," said Jennifer Locey, vice president of operations for the Holiday Inn and Holiday Inn Express & Suites in Williamsport, which together have 198 rooms booked almost entirely by ESPN for the duration of the World Series.
The hotels' management made arrangements for about 100 gas workers to stay at its Wilkes-Barre site about 80 miles away. Others took vacation, she said.
"Almost everybody's been really supportive," Locey said.
Kristi Gittins, a spokeswoman for Chief Oil & Gas, a Texas company that has been housing many of its employees in the Holiday Inn and the Hampton Inn, said many workers had already set up permanent residence in the area but that it still has workers "coming in and out" who had to find different lodging out of town.
"Little League is such a wonderful event for the entire area," said Gittins. "It's a temporary inconvenience for workers. We didn't give moving a second thought."
Gas workers approached in hotel parking lots this week were reluctant to talk to a reporter, but one said he was heading to Ohio for vacation.
An electrical contractor from Somerset County who was at the Hampton Inn said he wasn't sure where he would be going.
Since last fall, gas workers have made up 60 percent of the guests at the 200-room Genetti Hotel & Suites, carrying the historic downtown hotel through the winter slow season and helping push occupancy rates to nearly 100 percent this summer.
"We used to take vacations between January and March. Now there's no slow time," said Kathy Taylor, guest services manager at the Genetti, built in 1922.
Until gas drilling took off, the hotel's "bread and butter" had been the overnight tour-bus traffic between Washington and Niagara Falls.
Taylor said the hotel now is the home base for a number of gas industry "landmen" who do deed research work at the county courthouse, two blocks away.
Many have found other accommodations, Taylor said, but about half are staying put and paying the higher Little League rates. "They can't afford to be uprooted," she said.
But there was no question that Little League came first for the Genetti hotel.
"We've been hosting some of the same Little League administrative officials, like those in the umpires association, for 25 or 30 years," said Taylor.
Finding enough rooms for the baseball fans is "tight every year," said league spokesman Steve Barr. And there's always a last-minute rush, he said.
But there is no worry for the largest bloc - the 250 to 300 players and coaches. They are housed at the playing-field site.
Contact staff writer Amy Worden at 717-783-2584 or firstname.lastname@example.org.