There's no secret about that. I've had this game circled since beginning of season. It's a big-time game. According to a Husky staffer, fans threw cups of urine and dog feces at the Husky players and staff two years ago when Washington visited Autzen. And they've thrown dog biscuits for years.
People tend to go a little crazy when Washington is in town.
The rivalry supposedly began back in 1948 when Oregon and Cal tied for the best record in the Pac-10 Conference and the Rose Bowl participant was decided by a vote taken from conference members. It was generally assumed that the four California schools would vote for Cal and the Northwest schools would vote for Oregon. But Washington voted for Cal and recruited Montana to vote for Cal as well, and the Bears got the bid. In 1995, Washington coach Jim Lambright, lobbied hard for his Husky team to be chosen for the Cotton Bowl over the Ducks. In 1962, Oregon's Larry Hill was attempting to catch a pass in the end zone to win the game, but was tackled by the Washington fans who had rushed onto the field.