Early Sunday morning (July 1, 2012) a 63-year-old California man became the 15th victim of a mountain lion attack in California since 1890. His injuries were non-life threatening and he was released after a short visit to the hospital.
The Bay Area man was on a hiking trip in Nevada County and stopped for the night along the Yuba River. He laid his sleeping bag on the ground, crawled in and went to sleep. Around 1:00 a.m. he was suddenly awoken by a mountain lion clawing and biting his sleeping bag. After a minute or two of fighting the lion, the cat backed away. The man said the cat watched him for about 15 to 30 seconds from a 15 foot distance, and then it took off into the trees.
The man hiked back to his vehicle and drove to a hospital in Grass Valley to get his scratches and bites checked out. The California Department of Fish and Game responded to the hospital. Officers verified the man's injuries and collected samples from his clothing and sleeping bag. The evidence has been sent to CDFG's forensics lab in Sacramento for further analysis.

CDFG wardens investigated the man's camping spot and found lion tracks. They used hounds in an attempt to track down the lion but were unsuccessful, only able to locate the remains of a housecat which may have been attacked by a lion. They are continuing the search.
Why Did This Happen?
Mountain lion attacks on people are extremely rare and almost always the result of a sick lion or a case of mistaken identity. Lions see movement and shapes better than they do fine detail, and experts believe some attacks may have happened because the person was acting similar to a deer: a lion's preferred prey. For example, a bicyclist hunched over looks like a deer running through the trees.
Lions hunt by stealth and try to take their prey down with one quick bite to the neck. Rather than making a precision attack, this particular cat appeared curious and confused as it scratched and bit at the man in the sleeping bag.

Mountain lions, especially young juveniles still perfecting their hunting skills will sometimes scavenge from the kills of other animals and even other lions. Because lions cache their prey -- covering the animal with leaves and sticks between meals -- the hiker in the sleeping bag may have looked like a freshly cached meal. When the potential meal fought back the lion quickly retreated which may further support this theory.
Lion attacks remain exceptionally rare, even in California where the largest population of lions in the United States (approximately 4,000 cats) coexists with over 37 million people. Most victims are able to fend off lions by fighting back.
Lab results will indicate if this particular mountain lion was ill but the odds are he was merely a bit too curious. Perhaps this experience taught him to be wary of people and avoid free food, but if he's found by CDFG officials, curiosity will have inevitably killed this cat.
July 10, 2012 UPDATE - CDFG Calling Off the Search
After ten days of unsuccessful searching for the mountain lion, the California Department of Fish and Game has called off the hunt. Tracking dogs were unable to pick up a clear scent. At one point the dogs treed a large male lion, but from saliva evidence left on the man's sleeping bag the Department knew the lion they were searching for was a female. They let the male lion go free and were unable to find the lion responsible for the incident earlier this month.
Likely this young female lion was a dispersing juvenile, still perfecting her hunting skills and searching for an available homerange. After the scuffle with the hiker she was probably shaken and decided to find some where else to establish a territory. Hopefully she's learned people should be avoided and has found a new, more remote habitat to call home.