There’s an overlook park on the east side of Fauntleroy Way SW, just across the street from the ferry dock. The foliage can make viewing challenging, but is essential for the salmon. Check the tide tables and go at high tide, when it is easier for the salmon to get up from the Sound to the creek.
If you’re at that overlook, you can walk around the fenceline up Director St. The first long driveway around the corner is where the fish watchers keep their tally. You can ask them there how to get the best view down at the creekside.