Calls to Idaho's offensive-odors-reporting hotline have dropped by half since it was instituted in 2001 - from more than 2,000 complaints to about 1,250 last year, according to the state department of agriculture. And records for this year indicate that the number of calls are holding steady again.

Still, dairies bear the brunt of the odor grievances, with more than 1,000 of the calls logged as gripes against dairy aromas. However, officials say the majority of the complaints stem from only a handful of operations.