The dikes on the Skagit are a funny thing. Dikes are public improvements paid for by taxpayers, so they are a public asset. However, many of those public dikes are built on private property. Used to be you could walk atop almost any of them with no issues. That changed some years ago, maybe 20 even. Some private landowners got fed up with the behavior of some dike users, or got fed up with the very concept that someone was walking on a public asset built on their land and complained to Skagit County. Since then the County's view is that the dikes are on private land under private property control even though the dikes themselves are technically owned by the public. So you can only use them with landowner permission. Reversing that would take a well financed court case, and there's no guarantee of winning. This was told to me by my sister who lives in the county and had been walking her dog on the dikes since 1985.