This time the target was Gold River Orchard.
"They're going into people's homes, and they are going into their operations, and they are stealing their livelihood," said Bruce Blodgett of the San Joaquin Farm Bureau Federation.
"It's brazen; it's aggressive," he added.
Deputies say the thieves snuck onto the property after hours before taking off with three full large containers of the nut.
"Walnuts are a valuable commodity right now, a little bit in short supply. So, when you have that situation, prices are high; it becomes a target," Blodgett told CBS Sacramento.
Blodgett says the thefts are happening more and more, and the impact on the farmers can be devastating.
"They spent the entire year taking care of their trees, getting this crop to production, getting through the harvest...finally get it ready to go to a point where they are going to be able to sell it, and it's gone," said Blodgett.
"Bottom line, we are going to have to do more in terms of, one, capturing these folks and - two - more importantly, prosecuting them too," said Blodgett.
The San Joaquin Farm Bureau Federation plans to talk to members of the state legislature about what can be done to increase penalties and fines for these types of crimes.
There are no known suspects in the Gold River Orchard case.