Throughout the Valley, outdoor enthusiasts are embracing the hot summer weather.

Thieves, too, enjoy the temperature rise for new opportunities to burglarize cars left at trailhead parking lots.

An unattended car is “a perfect crime of opportunity for the crook,” said John Urquhart, spokesman for the King County Sheriff’s Department.

“Don’t leave anything in view,” he said. Trail users have responded to this popular piece of advice by hiding their wallets, cell phones and other valuables in the glove box, trunk or under seats. But hikers and mountain bikers need to do more to prevent theft.

“Thieves have caught on,” Urquhart said. “You really can’t leave anything of value in your car.”

Despite law enforcement officers’ efforts to deter thieves, trail users needs to take proactive steps.

“Go with your gut and use common sense,” Urquhart said.

Undercover operations and quick-acting citizens have prevented a number of crimes, but the department does not have the resources to patrol the many trailheads in King County.

“We can’t be there all the time,” Urquhart said.

In addition to sheriff’s patrols, the U.S. Forest Service also provides occasional monitoring of trailheads. However, the presence of law enforcement or forest service employees shouldn’t provide a false sense of security.

“The public needs to take initiative,” Urquart said.

The amount of criminal activity is weather-dependant, Deputy Brent Naylor said. Many of the trailheads dotting Interstate 90 are popular with thieves. It’s easy for them to jump on and off the freeway, he added.

The Twin Falls trailhead off Exit 34 is one of the hot spots for trouble. However, hikers are catching on to criminal activity, too. Naylor has noticed more ‘trail cars’ parked in trailhead parking lots. These are often older, ‘beater’ cars that hikers have kept around solely for trail use. Thieves won’t even bother with them, he said.

Regardless of the type of car you drive, Urquhart and Naylor said owners need to protect their property. Anything left in sight is bound to entice thieves to break in and search for more. Here are a few tips to prevent thieves from breaking in to your car:

• Call 911 if you notice someone acting suspicious.

• Never leave valuables in your car.

• Roll up the windows completely.

• Always lock your car.