Crater Lake National Park became a national park in 1902. At 1943 feet deep, it is the deepest lake in the USA and one of the deepest in the world. It is also one of the cleanest and most pristine in the world because it has been filled by only rain and snowmelt. Snow now blankets the landscape for eight or nine months of the year making for a short growing season. The elevation of the lake is 6173 feet.
Everyone is awed by the intense blue of the water. Since all water is from rain and snow, the lake is pristine. Light gets absorbed color by color as it passes through the clear water. First the reds go, then orange, yellow, green, and lastly the blue. Only the deepest blues get scattered back to the surface which is why the lake is a vibrant blue, but of course never more blue that the sky.
No streams run into or out of Crater Lake making it a closed ecological system. The lake level is only reduced by evaporation and a little leakage. Two species of fish populate the lake, rainbow trout and kokanee salmon, and both are remainders from the six species introduced here way back in history. Streams do run down drainages on the outside slopes of the mountains, as seen in this photo below from a lovely hike I took along Annie's Creek Canyon Trail,which provides the drinking water for the park. In 1931, one of the world's largest western white pine trees was found in this canyon, measuring 31 feet in circumference and estimated to be 1000 years old. The creek is named in honor of the first woman to descend to Crater Lake.
This waterfall is seen along the road descending the south side of the mountain.