Alaska Airlines flies between: Vancouver - Los Angeles, Calgary - Seattle, Edmonton - Seattle, Los Angeles - Auckland, Auckland - Sydney, Vancouver - Seattle, Victoria - Seattle, Vancouver - Portland, Seattle - New York, Seattle - Orlando, Seattle - Las Vegas, Seattle - Los Angeles, San Francisco - Auckland, Phoenix - Los Angeles, Los Angeles - Vancouver, Auckland - Brisbane, Auckland - Melbourne, Seattle - Miami, New York - Los Angeles, Seattle - Maui, as well as several other routes.
Alaska Airlines charges for all checked baggage, however, their fees for both your first and second checked bag are the same at $25 USD. You are better off checking two separate bags than having an overweight bag. Any bag over 50 pounds incurs a $75 overweight fee. Alaska allows one carry-on item per passenger as well as a personal item, which is generally a small item such as a briefcase or small backpack.