Mongolia's National Centre for Zoonotic Disease has recommended not using marmot raw materials and meat, and not to store it at home or to transport it to urban areas. Some, however, ignore these warnings over the belief that consuming the innards of the animal is good for their health.
The bubonic plague wiped out millions of people in Eurasia and Europe in the 14th century.
Plague cases are rare in the United States, but incidents do occur in Asia and Africa the CDC reports.
Deaths from the plague are much rarer now, though a few people in the U.S. still die from it every year, according to Centres for Disease Control and Prevention (CDC) statistics.
Sebastian Pique, 24, an American Peace Corps volunteer who has lived in the region for two years, said he and the tourists were invited to the local governor's office on Friday to be informed about the situation. The quarantine is expected to be lifted next week.
Its most common form is bubonic, which is spread by fleas and causes swelling of the lymph node.
The more virulent form is pneumonic plague, which can be transmitted between humans through coughing.