Blue Grotto [Suggest Edits]
The Blue Grotto consists of a seasonal stream that falls 40 feet over a greenish rhyolite cliff near Lost Creek Lake, Oregon. The rock is actually ash from the eruption of Mount Mazama, the volcano that created the caldera now known as Crater Lake. The Grotto is open all year but the view is best during the spring (March - May) when runoff is high. One can easily run underneath the falls.
Short Run: The closest trailhead is the Lewis Road Trailhead on Lewis Road. From there you take the Lost Creek Lake Trail west for 2.5 miles to a "Blue Grotto" sign. Turn right here and follow an obvious use trail up to the Grotto.
Gem Type: Waterfall