• Wizard Island

    Crater Lake

    National Park Oregon

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  • Vehicle-Free Days on East Rim Drive

    The park will host two vehicle-free days on East Rim Drive, September 20 and 27, 2014. Although East Rim Drive will be closed for these events, all other roads through the park will remain open to vehicular traffic. More »

  • Lost Creek Campground CLOSED Nights of 9/19 and 9/26

    Lost Creek Campground will be CLOSED from 3:00 PM Friday, 9/19 until 5:00 PM Saturday, 9/20 because of the temporary road closure to vehicles on East Rim Drive. It will also be CLOSED from 3:00 PM Friday, 9/26 until 5:00 PM Saturday, 9/27.

  • Stage 1 Fire Restrictions in Effect

    To ensure public safety and to provide the highest degree of protection to park resources, restrictions on campfires, smoking, and fireworks are in effect. More »

Von Dorn Water Sampler

Van Dorn water samplers are used in Crater Lake to collect water at eleven depths (surface, 5m, 10m, 20m, 60m, 100m, 200m, 300m, 400m, 500m, 550m). The lake is 574 meters deep at the sampling location. Usually, the lake is sampled once every summer month (July, August, and September). Water chemistry variables that are measured at each depth include dissolved oxygen, pH, alkalinity, conductivity, ammonia, nitrate, other nitrogen compounds, ortho-phosphate, total phosphorus, sulfate, chloride, calcium, magnesium, potassium, sodium, silicates, and iron.

Visit this page to learn more about Van Dorn samplers.


van dorn out of water


Van Dorn water samplers are attached to a cable that is then is lowered into the lake. By the time the cable reaches the bottom of the lake there are 11 Van Dorn samplers on the line. A weight is dropped at the top of the cable, which then travels down the line and trips, and closes, the ends of each Van Dorn sampler. The cable is then pulled back into the boat and the water in the Van Dorn bottles is collected for water quality testing.

van dornwater sampler


A scientist carefully removes water from a Van Dorn sampler.

van dornwater sampler


A park biologist collects lake water from a Van Dorn sampler for laboratory testing of the oxygen requirements of the sample.

Did You Know?

Did You Know?

The Clarks Nutcracker is frequently seen around the rim of Crater Lake. It feeds almost exclusively on the seeds of the Whitebark Pine. It gathers the seeds and hides some of them to eat later, helping the tree to disperse its seeds. Forgotten seeds may grow into new Whitebark Pines.