Department leaders say the statistics partly reflect improved policing techniques: Rangers are reporting problems they didn't previously notice or track.
On paper, Hearst San Simeon State Park, with 21 miles of coastline -- the most in the state system -- experienced one of the largest increases in crimes last year. But officials there blamed a procedural change: Now, a record is kept every time a ranger is called out, rather than logging only those calls that ended in a crime report or arrest.
No one, however, denies that ranger vacancies and attrition have undercut their vigilance.
"That's huge," said Karl Poppelreiter, the department's chief of enforcement. "We've had very competent people -- some of our shining stars -- who have left because they can make significantly more money and have significantly fewer pressures on them."
Last year's 7 percent uptick in crime probably is "not enough to notice" for most rangers, Poppelreiter said. But he is concerned that dealing with crime further erodes law enforcement's ability to educate visitors and correct a problem before it becomes a crime.
"Generally, everybody out there is feeling the crunch," he said.
San Luis Reservoir State Recreation Area near Los Banos is one of few summer boating venues for heat-stressed San Joaquin Valley residents. It also is a hotbed of boating-related accidents.
The park is short three rangers, and Superintendent Greg Martin said it has become difficult to do the kind of proactive enforcement that prevents such accidents.
In the past, "you might have been able to post someone up at the boat ramp full time, but right now we can't afford that," Martin said.
Today's rangers have the same training and enforcement powers as other law enforcement officers, but earn 20 percent to 50 percent less than city police or county sheriff's deputies. Add growing frustration with the realities of rangering and the gap becomes too wide for some to resist.
Bergstresser, for one, joined the Arcata Police Department in February after eight years as a state park ranger.
Two patrol boat shifts a week
The 20,000-acre Folsom Lake park was a place of unrelenting activity during the long and hot Fourth of July weekend.
Six years ago, the park had two daily boat patrols, seven days a week. On July 5, Ranger John Stephens drove the sole state patrol boat, which is used only two shifts a week.
"The biggest thing is crowd control," Stephens said. "It's hard to deal with so many people when you have so few staff."
Stephens spent 90 minutes towing a disabled boat -- and its injured passenger -- to a launch ramp where paramedics waited. Then he was off to enforce boat speeds along the beaches.
He soon apprehended three personal watercraft users. One got a warning, and one got tossed out of the park for speeding in swimming zones. The third received a citation for improperly towing a small raft laden with children -- none wearing life jackets.
Many parks seem to naturally attract potentially dangerous behavior, whether that means hiking a remote trail without a map or launching a Jet Ski off a boat's wake.
Nowhere is this more apparent than in the state's eight off-road vehicle recreation parks, which have a per-capita rate of crime and safety incidents seven times above the average for other parks.
Common violations include speeding, failing to heed muffler requirements and riding in closed areas.
Off-road parks also log many injuries.
Rangers at Hollister Hills State Vehicular Recreation Area crowded around Half Moon Bay resident Monty Muak on a recent afternoon. The all-terrain-vehicle rider had flown off his machine and hurt his shoulder. He told emergency workers he had been speeding.