Folks think Lake Tahoe is the bluest lake they've ever seen, and it may in fact be the most "ultramarine blue" I've seen. However, I think Cherry Lake on the Western edge of Yosemite is probably the most "sapphire blue" as I've seen.
(For size reference, the lake itself is about 4 miles long and a mile wide, and the balding mountain in the background a bit to the right is about 8 miles away near "Kibbie Ridge" in Yosemite.)
ILCE-7RM6FE 24-70mm F2.8 GM II lens30mmf/9.01/200s100 ISO0.0 EV
Shot with the Zeiss Batis 40/2. I love this lens. Colors and bokeh were left untouched in Lightroom—only a slight contrast increase, an exposure adjustment, and a subtle added vignette.
Waterton Canyon, easy gravel ride so decided to schlepp a film camera and a7rvi since the sheep can be prolific in here, but I think I didn't' get an early enough start and its a little warmer today.