Drive east from I-5 on Sunset Highway (Hwy 542) at Exit 256. Follow that road east through Deming. It eventually turns into the Mount Baker Highway and will take you right to this spot which is at the Mount Baker Ski Area.
This is one of the most photographed views in the US if not the world. You may have some company while you're shooting, and it's hard to come up with something original, but it's great fun anyway.