Rock County Sheriff Robert Spoden said deputies have seen a spike in heroin cases during the last 18 months.
The Rock County Sheriff's Office said the community's position on two major freeways makes it attractive to drug dealers looking to set up shop.
"It's a relatively easy drug to obtain. We know people are going to either Rockford or Madison," Spoden said.
More than half of the overdose cases in Rock County are caused by heroin.
"They come from a cross section of our community. They are people who are affluent, middle class, and people at the poverty level," Spoden said.
Eighteen of the county's fatal overdoses last year are linked to either heroin or opiates such as oxycodone.
"From 2010 to 2011, we've had about a 25 percent increase (in overdoses)," said Louis Smit, chief deputy coroner.
Smit said prescription drug abuse often leads to heroin use. He is advising residents to take their old medications to drug drop boxes.
"If you have drugs sitting around the house, that's a good way to get rid of them. That takes the temptation away, and it gets rid of them so they don't impact our environment," Smit said.
Spoden said Rock County is considered a high-intensity drug trafficking area, so authorities get extra federal resources to help curb the problem.
"I think we made a dent in (the heroin problem), but the mistake we made was thinking it went away, and we didn't stay focused on it like we should have, and we won't make that mistake again," Spoden said.
Sheriff's officials said they're hoping to use some of the drug money they've confiscated to get some new equipment and possibly add another drug-sniffing K-9 unit.