YAKIMA, Wash. — Emma Gonzales was excited to see the cost of regular gasoline — $2.99 per gallon — at an Arco in downtown Yakima.

“It’s like, let’s gas it up,” Gonzales said Wednesday as she finished filling up her Chevrolet van. “But who knows, by next week it could be back up.”

The Yakima resident isn’t sure why prices at the pump rise and fall, but she feels those jumps in cost.

“The gas price is one that really digs into your pocketbook,” she said.

Gas around Yakima County hasn’t been this cheap in nearly two years, according to the website Gasbuddy.com, which tracks fuel prices at the pump.

The county’s average price per gallon was $3.20 on Wednesday. That is below the state — $3.32 — and national — $3.28 — average prices.

In Washington, gas is often cheaper east of the Cascades, said Cassie Devaney, a spokeswoman for AAA in Washington. “The farther east you go, the lower the price for gasoline.”

The average cost of gas around Spokane on Wednesday was $2.99.

Cheap crude oil from Canada helps keep gas prices lower east of the Cascades, said Patrick DeHaan, a senior petroleum analyst for Gasbuddy.com.

Yakima gets much of its gasoline from refineries in the Rockies, which use Canadian oil. Their supplies are cheaper, and their product is as well, DeHaan said. “Cheap crude oil means cheaper gas.”

By comparison, refineries in Western Washington compete on the international markets for crude oil, which makes it more expensive, he said.

Canadian crude oil is cheaper because it’s mostly landlocked.

“It’s stuck in North America,” DeHaan said.

That could change, though, if a proposed oil pipeline is built to move Canadian crude to the Gulf of Mexico, where it can be cost-effectively exported.

Environmental concerns about the Keystone XL pipeline have delayed the project, which is fine by DeHaan.

“You take away (Canada crude being) landlocked, and what happens? The price will go up,” he said. “Suddenly there’s more hands in the cookie jar.”

That would mean higher gas prices at the pump in Yakima, he said.

Meanwhile, according to the U.S. Energy Information Administration, gasoline prices are projected to remain fairly stable through the rest of this year.

• Dan Catchpole can be reached at 509-759-7850 or dcatchpole@yakimaherald.com. Follow him on Twitter at twitter.com/dcatchpole.