15% off Idaho/California and Southern California/Montana flights

Here's the deal: Alaska Airlines will take 15% off your fare between airports they serve in Idaho and Oakland, San Jose, Fresno, San Francisco, and Sacramento; and between Southern California (LA, Long Beach, Burbank, Ontario, Orange County, San Diego, and Santa Barbara) and airports they serve in Montana. Use e-cert code EC01907 before April 15 for travel between April 24 and June 20 only.