BOULDER COUNTY, Colo. -- This is the time of the year when many people ship gifts and cards to loved ones across the country, but the Boulder County sheriff has a warning for some residents.

There have been several reports of thefts from mailboxes in rural areas.

The first instance occurred overnight on Tuesday, Nov. 7, in the extreme northeast corner of the county, north of Ute Highway and east of North 115th Street, deputies said. At least nine rural mailboxes were rifled through and much of the mail was found littered along the roadsides in the area, the sheriff's office said. Investigators said they believe that the thief had been looking for checks or other financial information. Envelopes from financial institutions were found opened and empty, deputies said.

"You got access to Social Security numbers, other financial account information which then people can use, via identity theft, to perpetuate additional financial crimes," said sheriff Commander Phil West.

A second series of thefts were reported on Sunday, Nov. 19. At least 17 mailboxes were broken into and mail was also stolen from those boxes, deputies said.

More reports of thefts are trickling in as word spreads and additional area residents find that their mail is missing or discarded along the roadsides, the Boulder County Sheriff's Office said.

"I was on vacation and during that time period someone took newly made checks from the bank out of the mail and then they starting writing checks," said theft victim Rick Kauvar.

The area that's been a target of the most recent thefts includes the rural neighborhoods of North 39th Street, North 41st Street, and Niwot Road west of 55th Street, approximately five miles north of Boulder.

Authorities said mail theft is an increasingly popular way of gaining information that leads to check fraud, credit card fraud, and identity theft, not to mention grabbing any currency or other valuables that may have been sent through the mail.

"We drive to town to mail our bills or we pay online," said Boulder County resident Henry Poirot.

In order to minimize your exposure, the sheriff's office recommends that people do not use their rural roadside mailbox for mailing packages, bill payments, or other financially sensitive documents. Also collect your mail as soon as possible and if you anticipate being gone for a few days, have a trusted friend or neighbor collect the mail in your absence, or arrange for the post office to stop delivery until you return.

Deputies ask that residents report suspicious vehicles and people to the sheriff's office immediately. Deputies are investigating the possibility that the most recent series of mail thefts may be related to a theft of a vehicle. The thefts are also related to a spike in the use of meth in Boulder County as well, authorities said.

"We've seen a real rise in mailbox theft over the years and it's kind of coincided with the rise of methamphetamine use," said West.

Kauvar said the area is not as peaceful as it used to be.

"As bad as the mailbox problem is, the problem of people speeding 60 and 70 mph on the roads is an even worse problem," said Kauvar.

Anyone with information about these crimes is asked to contact the sheriff's office at 303-441-3650.