Service stations in Oklahoma City were offering gas below $2 a gallon, though the national average for regular still tops that price by about 75 cents, USA Today reported.

Cars were lined up in droves when the OnCue station, on the city's Shields Boulevard, cut its fuel to $1.99 a gallon, the newspaper said. A "rival down the street" went even further, putting the price at $1.98, only to be beat out yet again by a competitor in Moore, a suburb of the Oklahoma capital. The moves are reminiscent of the 1970s "gas wars," USA Today mused.

Back then, "stations routinely vied to offer the cheapest gas, knowing their big price signs out front were sure to bring in customers," the newspaper recalled. "They also wooed motorists with gifts and gimmicks, like trading stamps or dinnerware."

The prices and tough competition seen in Oklahoma City would have been unthinkable before oil prices started to drop precipitously in recent months. Across the nation, gas prices may well drop to their lowest levels since the Great Recession if that trend continues, AAA spokesman Avery Ash told NBC News on Wednesday.

The barrel of crude would have to fall by an additional $25 to $30, however, for the national average to equal the $2 tag seen in Oklahoma. Gasbuddy.com expects that average to slip to $2.50 by Christmas, the representative added.

"Gas prices have fallen at a remarkable pace that would have been unthinkable just a few months ago," Ash said. "Lower gas prices represent real doorbuster savings as everyone begins their holiday shopping."

The Oklahoma City stations were the first in the United States to offer gas below $2 in four years, CNBC noted. There are a number of other states - including Missouri, South Carolina and Texas - where that price could soon be matched, Gasbuddy anticipated.

When it came to the best deal for drivers, Mississippi rounded out the top 5, the business channel noted, while the most expensive gas was found in Alaska, California, Connecticut Hawaii and New York.