Gas prices continue to tumble across Arizona. Triple-A Arizona says prices fell over six-cents a gallon on average to $2.18. In Flagstaff, the average price of gas fell four cents to $2.36 a gallon. Some stations are selling gas for $2.25 a gallon and lower. In Prescott, gas fell over seven-cents a gallon to $2.29. Some stations are selling gas for $2.15 a gallon, with Costco selling gas for $1.97. Triple-A officials say with demand low and stockpiles high expect prices to continue to fall for the foreseeable future.