| Clue | Source | Date |
|---|---|---|
| Structure that allows aquatic animals to climb in a river | ||
| Structure that creates a path for upstream migration, and a hint to hidden words in four long Down answers | The Washington Post | 24 Dec 2020 |
| Structure that creates a path for upstream migration, and a hint to hidden words in four long Down answers | LA Times Daily | 24 Dec 2020 |
| Structure for spawning salmon |