MAMMOTH HOT SPRINGS, Wyo. — In the fourth round of surveillance testing for the novel coronavirus in Yellowstone National Park employees, all tests came back negative.
On June 17 and 18, National Park Service employees, with assistance from local and state health officials, tested 190 employees from the NPS and concession companies operating in the park, according to a park press release.
Initially, one concession employee tested positive and was immediately isolated. The employee was retested twice more and both tests came back negative. The state health office described the initial test as a "false positive" and the employee has returned to work. According to the county health officer, a small percentage of "false positives" are normal in widespread surveillance testing.
The total number of Yellowstone employee tests completed since late May is 577. The week of June 22, 162 tests were conducted, and those results are pending. Moving forward, the park will continue to test employees in partnership with Montana and Wyoming.
As introduced in the park’s reopening plan, the surveillance testing will continue throughout the summer and target employees who are first responders and/or work directly with the public.
Additionally, the park sampled wastewater systems in Gardiner, Mammoth Hot Springs, and Old Faithful between June 13 and 16. Lab results indicated 0% prevalence of COVID-19 in those systems at the time they were sampled. Additional samples were taken at Mammoth Hot Springs and Old Faithful between June 27 and 29, which may give the park a better idea of COVID-19 increases due to reopening.
From June 16-29 park visitation has been down 11% from the same time last year. Parkwide 119,974 people visited during that time frame this year compared to 134,278 in 2019. Wyoming entrances were down only 1% from 2019 compared to Montana's three entrances which showed a drop of 15%.