The Dawn of the World, by C. Hart Merriam, , at sacred-texts.com
The Southern Mewuk of Merced River foothills say:
Some of the rivers are inhabited by Ho-hā'-pe, the River Mermaids or Water Women. The Ho-ha'-pe have long hair and are beautiful to look at. They usually live in deep pools, and are known at several places in Wah-kal'-mut-tah (Merced
[paragraph continues] River). In that part of the river which runs through Ah-wah'-ne (Yosemite Valley) they have been seen a number of times.
One lives now lower down in the river, at the upper end of Pleasant Valley in the large round pool called Ow'-wal. In the early days two partners used to fish for salmon at Ow'-wal, one on each side of the pool; several times they saw Ho-hā'-pe.
Another lives in the deep water at Wel'-le-to (on the Barrett ranch, a little below Pleasant Valley). At this place a few years ago some Indians from Bear Valley and Coulterville came to catch salmon. They put their net in a deep place in the river, and when it was full of fish tried to pull it out, but could not, for it was stuck on the bottom. Ho-hā'-pe the Water Woman had fastened it to a rock, but the men did not know this. One of them went down to find where the net had caught, and to lift it up. While he was doing this Ho-hā'-pe put a turn of the net-rope around his big toe and he was drowned. Then several of the men had to go down to get him. After they brought up his body all of them saw Ho-hā'-pe in the pool below, and saw her long hair float out in the current.
NOTE--The story of Ho-hā'-pe the River Mermaid, varying more or less in details, reaches north at least to American River, where the Nissenan
[paragraph continues] (who call her Ho-sā'-pah) have the following version:
Two maidens were walking along American River below the foothills when they heard a baby cry. They followed the sound and soon saw the baby lying on a sand bar in the edge of the river. One of them reached down to pick it up when it suddenly changed to Ho-sā'-pah the River Mermaid, who, seizing the young woman, dragged her into the river. She cried out and her companion took hold of her arm and pulled and pulled as hard as she could to save her, but Ho-sā'-pah was the stronger and dragged her under the water and she was never seen again.
The other maiden ran home to the village and told her people what had happened. She was so terribly frightened that her mind became affected and in a short time she died.