There is a monument to Adams at the mouth of the Okawa River, and the Anjin Festival is held in his honor every August.
There are no monuments dedicated to Adams anywhere near the Okawa River. 
mnli hypothesis: There are no monuments dedicated to Adams anywhere near the Okawa River.  premise: There is a monument to Adams at the mouth of the Okawa River, and the Anjin Festival is held in his honor every August.