Crater Lake Fascinations: Diller’s pin, clear water, fish stories keep lake and park a place of wonder forever fascinating – August 31, 2002

Crater Lake Fascinations: Diller’s pin, clear water, fish stories keep lake and park a place of wonder forever fascinating

Herald and News

Klamath Falls, Oregon
August 31, 2002


Frequent visits to Crater Lake National Park constantly reveal new tidbits of information that help to keep the lake and park a place full of wonder and fascination.

Consider Diller’s pin.

The nail-sized, barely visible pin was hammered into the caldera wall by J.S. Diller in the late 1800s while he stood in a canoe. For decades the pin, located in a cove below the Rim Village area, was used to measure lake levels. It wasn’t until September 1961 that the U.S. Geologic Survey installed a replacement, a gaging station at Cleetwood Cove.

In recent years it hasn’t been necessary to hike to the lake to figure lake levels. An Internet Web site keeps an undated reading. Historically, the maximum observed lake elevation was 6,179.34 feet above sea level on March 25, 1975, while the minimum was 6,163.2 feet on Sept. 10, 1942.

“It’s very stable,” says Mark Buktenica, a National Park Service biologist who has spent more than two decades studying the lake.

Crater Lake’s maximum known elevation is 6,180.5 feet, the average of several observations of lichens made between 1916 and 1960. The occurrence of living pine trees slightly higher suggests the lake has been higher for several centuries. As of Friday afternoon the level was 6,171.70 feet.

The Web site is at

Diller’s pin is pointed out by some interpreters on some of the lake boat tours. Diller was sent to the lake in 1853 by John Wesley Powell, the director of the U.S. Geologic Survey, to study geologic formations at the park.

Lake boat tours typically offer other fascinating tidbits, including information about fish and water quality.

Buktenica, who studies water clarity and the effects of fish, which were planted in the early 1900s, says 25 percent fluctuation in water clarity are common at Crater Lake. Before that was known, others had worried the lake was losing its famed clarity.

Over the years it’s been determined that slides from the caldera wall can temporarily reduce the clarity.

“Because Crater Lake is so pristine, it’s sensitive to change,” says Buktenica, noting studies have determined the lake is the clearest in the world as measured by optical specialists.

He and other researchers, from their vessel the Neuston, named for animals that live on the water surface, use 8-1/2 inch diameter secchi discs to determine water clarity. The small disc has been seen at depths of 144 feet, with the primary limiting factor being that the disc disappears from sight. A larger disc has been seen at depths of about 175 feet. The deepest readings have been taken in the last five years.

“By the time you lose sight of it, it’s about the size of the end of my pinkie,” says Buktenica.

Fish, which were first planted by William Gladstone Steel, the “father of Crater Lake National Park,” are believed the main factor in reducing lake clarity. Although five kinds were planted, only two species ? kokanee salmon and rainbow trout ? remain.

Fish populations vary from year-to-year, with estimates of 200,000 trout, which can be 30-plus inches long and weigh 5 to 10 pounds, and several million of the smaller kokanee, which are typically 8 to 10 inches long.

“An increase in fish can result in a decrease in lake clarity,” says Buktenica. “The greatest human caused change to the lake was the introduction of fish.”

Along with water clarity, fish have made the lake attractive to various raptors, including bald eagles and osprey, that wouldn’t otherwise have reason to ply lake waters.

The fish also attract fishermen, although not as many as Buktenica and others would like. Even rarer are swimmers. Taking a dip in Crater Lake can be a chilling experience.

According to the USGS Web site, the temperature Thursday was slightly over 60 degrees, about as warm as it gets. Those readings quickly chill several feet below the surface. And, no matter the time of year, temperatures below 300 feet are always 38 degrees.

Some information about Crater Lake is chilling, but it’s all fascinating.