Llao Rock – Prominent Geological Features of Crater Lake National Park
#14 on the map – northwest corner of the caldera
This great mass of dacite (a sluggish lava) was produced from a vent on the upper slopes of Mazama and hardened after moving only a mile or two. The dacite filled in a former explosion crater. This rock rises nearly 2,000 feet above the water- -the highest vertical precipice on the rim- -and was formed by the most massive single flow apparent in the caldera wall, with a maximum thickness of 1,200 feet.
Crater Lake National Park
Prominent Geological Features Map
Note: the numbers associated with each feature name above correspond to their place on the Custom Google Map