Thursday, June 3, 2010

Lava Butte

Lava Butte is a cinder cone which is situated west of US Highway 97 between the towns of Bend and Sunriver, Oregon, USA. It is 500 ft high and has a crater 180 feet deep, measured from the high point on the rim. Lava Butte is part of a system of small cinder cones on the northwest flank of Newberry Volcano, a massive shield volcano which rises to the southeast. Lava Butte is part of the Newberry National Volcanic Monument. In 1977, Lava Butte last eruption was dated at 6150 radiocarbon years old, which is equivalent to 7000 calendar years.

The eruption began with a fissure spewing hot cinders to form the cone. In the next phase, a river of hot basalt flowed from the base of the small volcano to cover a large area to the west with a lava flow which remains largely free of vegetation. The lava flows reached the Deschutes River about 2.5 miles (4.0 km) to the west of the cone, burying its former channel under over 100 feet (30 m) of lava and damming the river to form a lake, known as Lake Benham. The river eventually overflowed the lava dam and eroded down into it, draining the lake and forming Benham Falls.

Lava Butte is a major point of interest in Newberry National Volcanic Monument. The summit of Lava Butte is usually accessible by car from mid-May to late-October. The road can be hiked during the off season. A trail with interpretive signs circles the crater.