Crater Lake National Park: Administrative History by Harlan D. Unrau and Stephen Mark, 1987
INTRODUCTION: Description of the Park
C. SIGNIFICANCE OF PARK
Crater Lake is unique among American lakes. The “crater” is a caldera which was formed more than 6,000 years ago when the top of the 12,000-foot volcano Mount Mazama collapsed. Roughly circular in shape, about six miles across at its widest point, and covering an area of some twenty square miles, the lake is surrounded by nearly twenty-six miles of colorful lava cliffs rising from 500 to 2,000 feet above the surface of the water. From this rimmed summit the land slopes downward in all directions. Over the centuries the caldera has collected water from rain and snow. Evaporation and seepage are now in near balance with precipitation, providing a fairly constant water level. The lake is an incomparable example of a deep, pure, and stable caldera lake.
Crater Lake is the deepest lake in the United States, the second deepest in the Western Hemisphere, and the seventh deepest in the world, dropping downward to 1,932 feet just southeast of Merriam Cone. The beauty and scenic grandeur of the lake and caldera constitute the prime feature and attraction of the park and one of the prime scenic fascinations in the United States. It has been designated a national hydrological landmark and is being studied by an increasing number of scientists under the park research program.