I've paddled a small portion on the Tualatin River, but I've never seen anyone else fishing there. If you are looking for places to fish, try Oregon's department of fish and wildlife's web page: https://myodfw.com/articles/50-places-go-fishing-within-60-minutes-portland. Good luck!
There are fish in the Tualatin River, which flows through the park.
In the pond I saw, there appeared to be only bullftogs. They were tadpoles the size of a large orange. If you were interested in fishing, the pond I saw seemed too shallow for that anyway.
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