Complex sentence: Alaska Airlines operated by Horizon Air, has 5 or 6 flights a day from Santa Rosa, 2 or 3 flights a day to Los Angeles and 1 flight a day to Seattle, Portland, and San Diego.
Split into simpler sentences: Alaska Airlines operated by Horizon Air, has 5 to 6 flights a day to and from Santa Rosa. Everyday there are 2 to 3 flights a day to Los Angeles and 1 flight a day to Seattle, Portland, and San Diego.