I discovered this frog as seen in the first photo, sitting on a rock just underneath the surface and thus partly submerged. It held this position for at least 10 minutes while I returned to camp to fetch my camera, which I foolishly had left behind. After taking a couple of pictures it made a sudden movement and I thought I had scared it off. But it wasn't scared; it was lunging after a water bug snack. Then it swam a foot or so closer to me and posed as in the second photo.

This impressive frog was one of several that I saw along the edge of this small lake near Hyalite reservoir. Thanks to Joshua Puhn for convincing me that it was indeed a Columbia Spotted Frog.