www.singingfalls.com/seine

Oh, I am exhausted today already. Got up at 5:00 AM feeling like someone beat me over the head with a 2x4. The last post hole was a bear. After about 12 inches a dense layer of stream alluvium had to be penetrated. We spent almost two hours extracting densely packed creek bottom rocks that were probably there when time began. Ugh!
We'll be going at it again today in the hope that the fencing will be finished.
The thought crossed my mind that these very same alluvial deposits nourished young salmon and were utilized for alevin rearing.
Then some catastrophic rain on snow event flooded the plane. Or perhaps beavers built dams to cover the rock layer with silt and the like.
Whatever the case. Extracting the material in order to only place it back again almost immediately; simply to hold a wooden fence post that will decay shortly (relative time) seems so typical of human endeavor.
Incidentally, we also extracted two ancient Pacific Yew posts from the location of the old fence line. After probably 60 or 70 plus years of direct contact with the ground they showed no signs of decay at all. The heart wood is still in tact and very beautiful.
I'm very anxious to study out the possibilities of using open source software for the stream survey.