You'll drive down a long farm road and under a wooden train trellis before arriving at the doors of Helvetia Tavern (10275 NW Helvetia Road, Hillsboro, 647-5286, Since it first opened its doors on the day Prohibition was repealed in 1933, the sons and daughters of Hillsboro's Swiss farming families have patronized this restaurant and bar nestled among the wheat fields north of Sunset Highway. The atmosphere is a reflection of that relationship. Hundreds of baseball caps hang from the ceiling, and if there's a game happening somewhere, it'll be on the TV. Helvetia is home to the half-pound Jumbo Burger ($8.75), with Budweiser on tap and young waiters probably sporting Oregon State University gear. A sign warns you that this isn't Burger King: Here, you get what you get. But what you get is probably what you were after, anyway.