1. This is Crater Lake, the deepest lake in the United States and the seventh deepest lake in the world. It has a depth of 1,943 feet. The lake partly fills a deep caldera that was formed when a volcano called Mount Mazama collapsed around 7,700 years ago. A caldera means a basin or deep place formed by the explosion or collapse of a volcano. The waters of this lake are especially blue and free of pollutants because the lake has no inlets. The water is replenished by rainfall and snow.

2. A secchi disk is used to determine how clear water is. This is a disk that is like a cd. It is dropped into the water while connected by a rope. Scientists measure the depth of clarity by seeing how far the disk can be dropped while a person is still able to see its reflection. At Crater Lake, readings are in the high 20 to mid 30 meter range. This is very clear for any natural lake. These bright blue waters greatly enhance Crater Lake National Park which has beautiful surrounding woodlands also. 

3. Crater Lake is located in Klamath County which is in the southern part of Oregon. Klamath was named for the Klamath Indian tribe. They may have inhabited the region at the time when Mount Mazama collapsed. In their legends, the collapse was part of battle between the sky god and the god of the underworld. 

4. During the winter, the park gets over 500 inches of snow and entrance to the park is forbidden. The park service encourages visitors during the beautiful summer months. There are several areas within the park with restaurants and shops. There is also a boat tour on the lake. Visitors canelicit information about the lake and its history from the knowledgeable tour guide.

Answer the Questions (answers are at the bottom of the page):

1. What is the main idea of this story?

A. A secchi disk determines how clear water is.

B. Crater Lake is a beautiful lake in Klamath County, Oregon.

C. Crater Lake is a beautiful, geologic site in Oregon which many people visit every year. 

D. Crater Lake has brighter waters than most lakes.

2. What is an inference, not a fact, from the story?

A. Heavy snowfall makes the park dangerous to visitors during the winter.

B. The park gets over 500 inches of snow in the winter.

C. A secchi disk is used to determine how clear water is.

D. Crater Lake was formed by the collapse of Mount Mazama.

3. According to the legend of the Klamath Indians, how did Crater Lake form?

A.  Mount Mazama had a battle with the god of the sky.

B. The god of the underworld lived in Mount Mazama.

C. The god of the underworld hada fight with Mount Mazama.

D. The god of the underworld and the god of the sky had a battle.

4. Which fact is true about Crater Lake?

A. It is the deepest lake in the world.

B. It is the clearest lake in the world.

C. It is the seventh deepest lake in the world.

D. It is the second deepest lake in the U.S. 

5. Crater Lake has a depth of __________ feet. It is this deep because Mount Mazama collapsed about ____________ years ago.

A. 7,700 ... 1,900

B. 500 ... 7,700

C. 1,943 ... 7,700

D. 1,943 ... 770

6. Why are the waters of the lake bright blue?

A. The lake has no inlets.

B. The lake is free of pollutants.

C. The water comes from rainfall and snow melts.

D. All of the above.

7. Match the words with their definitions:

     determine             a. to make better

                                    enhance                b. to get from someone or something

                    forbid                    c. to decide based on facts

elicit                     d. to support

                  encourage            e. to say no, to not allow