If you are planning a driving trip soon and wondering about the price of gasoline, here's a reality check based on a just-completed, 2,700-mile road trip.

We paid an overall average of $2.45 per gallon for regular, unleaded gasoline. The trip took us through parts of Washington, Oregon, Nevada and California — all on the east side of the Cascade Mountains and Sierra Nevada. We spent very little time on freeways, instead driving a mix of backroads and major state highways.

The cheapest fill-up was in Richland, Wash., at $2.10 per gallon. We paid the most in tiny Bridgeport, Calif. — $2.999; let's call that what it was: $3 per gallon.

Gas prices were inconsistent when analyzed by small town, cities, along major highways or backroads.

The only trend was by state.

Averaged by state, our costs broke down this way: The average fill-up in Washington state was $2.22 per gallon; in Oregon $2.28; in Nevada $2.38 and in California $2.68.

We had been home only two days when I heard this national TV news report: "The average national price of gas is now $2.15 a gallon." Certainly not in our experience on roads in the wide open spaces of the American West. Either the samplings are very incomplete, or some other parts of the country are getting very cheap gas.

Our mileage fluctuated significantly depending on terrain, weather conditions and whether being in cruise control was practical, which it was not on twisting, narrow mountain roads.

Our worst mileage? Climbing mountain passes in the 7,000 to 8,000 foot range and facing strong headwinds. Predictably, the best mileage was obtained driving at slow speeds, in calm weather, at lower elevations and in cruise control.

And here's one more lesson from the road: Top your tank frequently, preferably when you still have a half-tank of fuel, especially if you are taking roads less traveled. We found more than one small town with stations out of business, closed for lack of gas or with only one pump operating because they were almost out of gas.

As the attendant at Burns Junction, Ore., said: "We had one guy who coasted in here on fumes because he'd planned to buy gas at a station that had run out."

Karen M. West is a retired Seattle Times editor.