West coast U.S. Senators, including Oregon's Jeff Merkley and Ron Wyden, are calling for an investigation into gas price spikes. Senator Jeff Merkley is one of six U.S. Senators asking the U.S. Department of Justice to look into the reasons gas prices soared over four dollars in the summer.   A recent study done for a California investigation of fuel prices shows crude oil prices were dropping while west coast gas prices increased from May to October.