The River of Stink

Can anyone tell me why the River of Skulls lately seems to be the river of stink. If you've been there the Calaveras has been getting smelier and smellier over about the last month.

I noticed a sulfurous putrescence about a month ago. Because the river was very low at the time I attributed it to exposed decaying alge or something. But the river has been both extremely high and extremely low over the last month and the stench is still there regardless of level.

It's a hydrogen sulfide smell and it seems to be strongest at the base of the dam.

Any ideas? I'd sure like to know if this is a natural occurence or something going terribly wrong with the water ecology.

I also saw a river otter there today. I had no idea they were around these parts but I'm pretty certain thats what the little critter was. I have seen beaver around quite a bit but this was no beaver. He popped his head up out of the water to check me out then swam by going downstream like a living torpedo. Really cool.

I don't imagine he's enjoying the stech though.