While at the round table late Saturday night at the SBSCBGT this Cathlamet gathering in mid May came up. Some asked about possibly boating to Portland, OR as a day trip activity. I shared that it was a long way from my house to Portland, let alone all the way from Cathlamet. How far? Well I dug out my Evergreen Pacific River Cruising Atlas and, using the back of my Leatherman tool to measure, and rounding the varying scales for each page in the chart book to the approximate 1 statute mile per 1.25" of map I came up with the following (but realize I normally calculate distances on charts while bobbing up and down in sloppy water in dim light with bleary, sleep deprived eyes, so my figures are probably off since this was done at home in the den, clean, dry and comfortable):
Cathlamet to Kalama: 36.8 miles upriver/east
Kalama to the the Multanomah Channel & mouth of Lewis River 15.2 mi. upriver/south (possible Spring Chinook boundary line)
Mouth of Lewis/Multanomah channel to Portland or I-5 (most likely Spring chinook legal boundary) is 19 miles upriver
or going West/downriver from Cathlamet to awesome sturgeon fishing grounds just upstream of the Megler Astoria Bridge is 22 miles.
I'm sure sturgeon are catchable closer to Cathlamet, I just don't know that water. C.W.