Diamond Craters National Monument (Proposed)
Suggested Citation: Kerr, Andy. 2000. Oregon Desert Guide: 70 Hikes. Seattle: The Mountaineers Books. pp. 108-109.
"A museum of basaltic volcanism."
Location: Harney County, 55 miles southeast of Burns
Size: 26 square miles (16,656 acres)
Terrain: Rugged lava flows
Elevation Range: 4,150-4,700 feet
Managing Agencies: Burns District BLM (present); National Park Service (proposed)
Recreation Maps: Northeast Quarter, North Half Burns District BLM
From a distance it doesn't draw you. More sagebrush covering some lava flows and craters—something far from uncommon in the Oregon Desert. At first glance it "resembles a thin, rocky pancake with a few bumps," says Dr. Ellen Benedict of Pacific University. However, if you know what you are looking at, it is quite another matter. Another distinguished professor of geology calls Diamond Craters the "best and most diverse basaltic volcanic features in the United States and all within a comparatively small and accessible area."
The educational and research values are immense. In Diamond Craters, all those volcanic terms that some teacher tried to pound into your head during geology class begin to make some sense. You can see it. It is all here.
As molten lava repeatedly spilled from deep in the Earth over the past 25,000 years, nature has been at work in what is now called Diamond Craters. Basalt does fantastically different things, depending on such variables as mineral content, the presence or absence of water, how it reacted upon coming up against other natural forces, how much and what kinds of pressure, how fast it cooled, and so forth.
With a little interpretation you can see the difference between lava flows, pressure ridges, pahoehoe lava (smooth, billowy, or ropy surface), aa lava (rough, jagged, spinose, clinkery surface), tensional fractures, lava toes, ash fall lava tubes, trenches, collapse craters, natural bridges, shield volcanoes, spatter cones, ramparts, kipukas (areas of undisturbed vegetation surrounded by lava fields), plug domes, driblet spires, benches, tephra, grabens, cored bombs, scoria, breadcrust bombs, maars, calderas, walls, rings, and cones.
Significant portions of Diamond Craters are vegetated. It is an ecotone between western juniper/big sagebrush, sagebrush steppe, and desert scrub zones. Two hundred and forty species of vascular plants have been identified. A small stand of aspen on the south end is unusual because of the low elevation.
One hundred and eighty-nine species of birds and 52 species of mammals are thought to utilize Diamond Craters. It may also have a unique form of subterranean mite (bumper stickers to follow: "Save the Diamond Craters Mite!").
The craters even have some water. Most notable is Malheur Maar, a spring-fed lake with over 50 feet of sediment that has piled up over the last 7,000 years. According to Benedict, Malheur Maar is "one of the most significant desert lakes between Mexico and Canada, especially for the study of past climates."
What to Do
The best way to see Diamond Craters is by car, with short excursions by foot. An excellent informative and entertaining brochure ("Please don't break open or collect the bombs") describing a self-guided auto tour is available from Burns District BLM. The tour is about 30 miles in length from OR 205 and starts at the turnoff to Diamond on OR 205 between mileposts 40 and 41 (measured from OR 78 near Burns).
The Desert Trail traverses the area (see Appendix D).