Sullivan County Public Health Services is alerting anyone who visited Holiday Mountain Ski Area in Monticello on Sunday, January 17, between 9:00 a.m. and 1 p.m. that they may have been exposed to someone who has since tested positive for COVID-19. If someone thinks they have been exposed, they should self-quarantine for 14 days and call their health care provider if symptoms develop, or call Sullivan County Public Health Services at 845-292-5910.