An electrical engineer exploring in his backyard - Fallen Leaf Lake - recently found a 2,300-year-old tree in pristine condition on the lake's bottom.
Using a remote-operated vehicle with a grabber, the team assembled by John Kleppe pulled the chunk of wood from a log that lies at 300 feet. The wood was carbon 14 dated to 300 B.C.
Dating the log is part of a effort by Kleppe and others to map historic climate changes in the region. He believes it can be done through the study of ancient trees submerged in the lake.
Kleppe had hoped the tree would be much older, say 13,000 years older, so it could be linked to a glaciation period. But, as only he and members of his team know, the study of Fallen Leaf Lake has produced more questions than answers.
"I have a stack of questions longer than you can believe," said Kleppe, who has studied the lake for about five years and is chairman of the electrical engineering department at the University of Nevada, Reno.
His work for the university is funded by UNR and grants from the U.S. Geological Survey and the Desert Research Institute.
In July, in an effort to identify an unknown organism in the lake, Kleppe hired a scuba diver to collect translucent, jellyfish-like objects. The diver pulled about 20 or so from a tree floating upright just offshore.
The organisms still have not been identified because they were stored in formaldehyde, which killed them before a specialist in Colorado could get one under a microscope.
Kleppe plans to try to have the organisms identified again in the summer.
The greatest challenge in studying submerged trees in the lake - or organisms that attach to those trees - is locating them to sample, he said.
A crew he assembled in October failed to find a targeted tree for an entire day. They were able to locate one only after a diver went down and tied a buoy to it.
Using a water crane, they chained the tree and pulled it near to the shore so chunks could be sawed off and studied. The rest was returned to the lake.
"The wood is so beautiful," said Kleppe of the tree, which dated to 1215 A.D. "It's perfectly preserved. It smells and looks like wood today. And it started growing in the 10th century."
Water acts as a preservative to wood when it is submerged for hundreds of years. The resin leaches from wood, keeping it from degrading.
Other explorations are under way, including the Tahoe Deep Blue project, northeast from Fallen Leaf Lake up Taylor Creek and into Lake Tahoe.
Christopher Nicholson, owner of the Massachusetts-based Deep Seas Systems, planned to take a 2,500-pound rover to the floor of Tahoe last fall, but financing didn't pan out.
Now Nicholson aims to build a new, lighter rover that will be cheaper to operate. The Tahoe exploration project, to last from two to six months, could happen in late summer.
New Millennium Dive Expeditions has already started exploring Tahoe, albeit in wetsuits.
In 2002, the 17-member team dived five times to reach a historic steamship scuttled in the lake. The vessel is wedged in sand about a mile out from Glenbrook Bay. It is poised for listing on the National Register of Historical Places.