The family of a Morgan Hill teen who has been missing for more than a month plans to increase the reward being offered for her safe return.

Steve LaMar, the father of Sierra LaMar, plans to announce the increase Saturday morning, according to the KlaasKids Foundation, which is helping organize volunteers searching for the missing girl.

The reward, first offered April 7, is currently set at $10,000.

Sierra, 15, has been missing since March 16, when she disappeared on her way to school. Investigators have said they are treating her disappearance as an abduction.

The Santa Clara County Sheriff's Office has conducted extensive searches in the area surrounding Sierra's home since her disappearance, including searches of reservoirs and other bodies of water. Hundreds of volunteers have also turned out for the search.