Didn't Evan notice the snail under the salamander till looking at the picture later ..hard to see what kind of snail but assuming it may be a robust lancetooth
Found by noting where a stream of water had squirted from.
This one was quite active, continuing to spout about every 45 seconds or so.
Not sure where it was getting all that water. There is a second siphon visible in a couple of the pics, but that's above water as well, so maybe from a second clam?
About ½ inch in dia, (13 mm)
It would close up just before squirting.
Photos of another here:
https://www.inaturalist.org/observations/215804711
Looks like the same species as this one:
https://www.inaturalist.org/observations/215804707
also found by noting the location of a jet of water.
Moving a rock out of the way exposed two rather long siphons of around 3 inches (60 mm) or more. I though it might be close to the surface and tried to scoop it out, but wasn't able to catch it by hand.