Help me understand these tides

[Pete112288]

So I have started fishing a place that is kind of a backwater of the lower columbia and just cannot figure out why the water flows the way it does. It is an interesting scenario for sure
It is a channel that is about 10 miles long. One end dumps right into the columbia, the other end is a large lake. On the far other side of the lake is a flushing channel that only allows water into the lake from the big river, it does not let water go from the lake towards the river.
I fish the fist couple miles of the long channel closest to the lake.
I get the tide predictions for a location within a mile of the mouth of the channel.
Where I fish, the tide kinda goes opposite of what I initially expected. When the tide is going out, the water flows in the direction of the lake, so into the lake from the river. When the tide is coming in, the water flows from the lake towards the river. I have only had good luck on outgoing tides here while the water is flowing into the lake.
To further make things odd, not only is it opposite direction as I suspected, the tide goes slack for longer on the low tide. If a tide says its going to be, lets say, minus 2ft, the water here is slack and still for the entire timeframe that the tides show a negative level. The water only moves when the tides are above zero.
Is there anyone that can explain this?

[Stein]

This happens in several rivers and around the islands of Puget Sound.  The Columbia is a huge river with a ton of water so it will dominate the tributaries and can easily overpower smaller flows.  When the tide is going out, sounds like that movement is pushing water up the tributary.  It may be due to the angle of where the trib and river meet or something else.  That movement may be pushing fish up into the trib increasing your catch odds.  There are also dams to influence flow.

I fish a place where the water moves in the same direction during both the ebb and flood.  There are other places where it will flow one direction in a small ebb and the opposite during a large ebb.