Glacial Potholes, or "And you thought 128 was bad?!"

On my way back to the car, I spied a sign on a side street:

ANCIENT GLACIER POTHOLES GEOLOGICAL WONDER 400 FEET

Now, I ask you, who can resist that? It's almost not fair! I had to see it. And it was worth the trip. I'll let the sign do the talking here:

Potholes were ground out of granite during high water of the glacial age by whirlpool action of water and gyrating stones of varied sizes.
Some of the grinding millstones may still be seen in the smaller potholes.
Over 50 such potholes exist in this confined area known in Indian days as "Salmon Falls."
These potholes vary in size from 6 inches to 39 feet in diameter, the latter being the world's largest pothole of record.

And for your viewing pleasure: