The falling ash from a Chilean volcano eruption has blanketed Argentine towns and suffocated local economies, with the ash endangering livestock and keeping tourists away.
The emergency in Neuquen province follows a similar measure by the national government in other parts of Patagonia where agriculture has been hit by accumulating volcanic ash.
The decree by Gov. Jorge Sapag will mean that those affected can receive tax benefits, among other measures.
The ash has also blanketed towns across the border in Argentina. In the area of Villa La Angostura, located 24 miles (38 kilometers) from the volcano, up to one foot (30 centimeters) of ash has accumulated on the ground.
The ash has made it difficult to drive safely on roads, and the eruption came just as resorts in the mountain towns were preparing for ski season.
"Today we can't anticipate the season's final results, but we can say that this has ruined the start of the winter season in the coming days," said Roberto Alonso, mayor of Villa La Angostura.
Residents in the town have been working to clean up the ash, said Alejandro Curiluck, a business owner in Villa La Angostura. "In 15 days we should be operating. The big problem is that the volcano keeps sending up ashes," he said.
Satellite images on Thursday showed the main ash cloud from the erupting volcano stretching about 900 miles (1,400 kilometers) toward the east-southeast, Chile's National Geology and Mines Service said in a statement.
"The eruption process continues and it's possible that an increase in activity could occur again, with episodes similar or greater in intensity than those that have occurred so far," the agency said.
The ashes are causing problems for Argentine farmers whose sheep herds are now roaming in pastures covered with ash.
According to official figures, there are more than 2 million sheep in Patagonia, of which more than half are affected by the ash.
In response, Argentina's Agriculture Ministry declared an emergency on Wednesday in the provinces of Chubut, Rio Negro y Neuquen.
Regional airports in Patagonia have also been shut down for more than a week due to the cloud of fine grit, which can damage airplane engines.
Buenos Aires' main airports reopened on Wednesday and international flights were operating again.
Based on reporting by the Associated Press.