BOZEMAN, Mont. -

With the winter season comes a typical rise in the cost of propane, but one Southwest Montana seller says this is an unusual spike. Ken Weskamp owns Madison River Propane in Belgrade. He has been in the business for more than 20 years and says he has only seen prices spike like his two or three times.

Right now he says propane prices are at $2.40 a gallon in Southwest Montana. That is up 40 cents from last year. Weskamp explains prices are usually determined by the cost of crude oil and demand. December's sub-zero temperatures created a high demand in our area.

He says with these prices, customers are thinking twice about how much they buy.

"People start conserving when prices go up 20 percent. They only budget so much for the winter season, so it is going to impact them drastically. We probably don't do tank fills, we are probably going to see people order a minimum amount until prices start to ease up," said Weskamp.

While prices have spiked, Montana remains below the national average for propane prices. We checked with the U.S. Energy Information Administration. According to their website, at the end of last week the national average for a gallon of propane was right around $2.70 a gallon.