Mike -
You might want to check out the following:
http://nwis.waterdata.usgs.gov/nwis/peak?site_no=12194000&agency_cd=USGS&format=html

In the last 200 years the Skagit at Concrette has been over a stage hight of 50 feet at least 3 times. In the early 1800s the flow was roughly 3 times that from the event last October with a stage hight pushing 70 feet.

Tight lines
S malma