The Keystone XL pipeline, if built, would cause gas prices in the Midwest to rise by as much as 40 cents per gallon, according to a report by Consumer Watchdog. The California group claims the pipeline will restrict oil supplies in the U.S. as exporting to other countries picks up. The result: rising oil prices with the ripple effect extending to gas and diesel prices. Meanwhile, average gas prices in the St. Louis area have increased from $3.20 a gallon last week to as high as $3.79, one of the largest spikes nationwide. Concerns about Egypt and the Middle East have played a role in the rising cost of crude oil.