Kate Ramsayer / The Bulletin

One lava tube southeast of Bend — once used as a garbage dump — has both a spacious cavern and a smaller, lavacicle-filled room in the back.

Another cave was “hard to see unless you really got down and poked your head in,” said Matt Skeels, the chairman of the Oregon High Desert Grotto caving group. He and other cave explorers had to crawl through a tight passage to reach a little room.

The High Desert Grotto members explored and mapped these and six other caves on the Department of State Lands’ Stevens Road property just outside Bend’s city limits, and for their efforts the group received the State Land Board’s 2008 Partnership Award earlier this week from Gov. Ted Kulongoski, State Treasurer Ben Westlund and Secretary of State Kate Brown. The three make up the State Land Board.

The award, said agency spokeswoman Julie Curtis, goes to “volunteer groups that go the extra mile to work on projects that will benefit the department.”

The caving organization, an affiliate of the National Speleological Society, volunteered to plot the caves in the 640-acre parcel of land, which the state agency hopes to eventually turn into a mixed-use development, although the property is not in Bend’s planned urban growth boundary expansion.

But the mapping effort, which could have cost thousands of dollars if the state had to hire contractors, will help state planners work around the caves, Curtis said.

“We could know where they are so that we could not only preserve them, but focus development in areas where we can avoid them,” Curtis said.

Skeels, who mapped the caves along with Geoff MacNaughton, Neil Marchington and Jeremy Wendelin, said his goal was to record the caves and to make sure they weren’t forgotten once the parcel gets developed.

“I wanted to protect those caves for their cultural resources, their geological resource, and for the bats using those caves,” he said.

Mapping the Stevens Road caves is just one part of his project to map a regional lava tube system, Skeels said, which stretches in and around Bend and north to Redmond.

“I was trying to have kind of a reference guide for that, because there’s a lot of caves in there,” he said.

Lava tubes form when the outer portions of a lava flow harden as molten lava continues to flow beneath it, eventually draining out and leaving a cave behind, according to the U.S. Geological Survey’s Cascade Volcano Observatory, while a lavacicle is like a stalactite, but made of volcanic rock.

Skeels and other members of the High Desert Grotto explored the local cave with GPS to mark its location, a tape reel to measure the size of the cave, a compass to measure direction and a clinometer to measure the cave floor’s slope.

Skeels then used a computer program to sketch out the geological feature.

While surveying the property, the cavers rediscovered a cave that had been hidden by garbage and discovered another that had been overlooked because of its tiny entrance, he said.

The longest cave was about 350 feet, while the shortest went back 60 feet or so, he said — smaller than the better-known caves off of China Hat Road but still fairly spacious.

One had been heavily used by people who left broken glass and smoke damage from campfires, he said, while in another people hunting for American Indian artifacts had dug pits into the cave floors.

“Each one had their own sort of character,” Skeels said.