A contractor working in Yellowstone National Park has tested positive for COVID-19, becoming the first confirmed case in the park after several hundred tests of workers. Meanwhile, Park County has separately had six new cases identified over the past week.

Park County Public Health Nurse Manager Bill Crampton said he received word Monday that a member of the construction crew working in the Fishing Bridge area tested positive for the new respiratory disease.

After showing symptoms of COVID-19 at their work site, "the employee recently returned to their home state of Montana, tested positive, and remains in Montana," Park County Health Officer Aaron Billin said Wednesday night. The case is not included in Park County's or Wyoming's totals, Billin said.

Crampton told Park County commissioners on Tuesday that health officials from Montana were tracing the contacts that the worker had with other people. In a Wednesday news release, Yellowstone officials said the person does not appear to have had close contact with park employees or visitors.

“This is why we have developed response protocols with our health experts and have required COVID-19 mitigation/response plans for all contractors,” Superintendent Cam Sholly said in a statement. “The contractor took the appropriate actions by immediately isolating the employee, sending him for testing, and notifying health officials.”

The positive test on the Yellowstone contractor was in addition to the six cases detected in Park County over the past week. All six of the people were tested at Powell Valley Healthcare in a seven-day span, from Thursday, June 11 to Wednesday, Billin said.

“We don’t think they’re due to visitors or the park opening up,” he said.

Five of the recent cases — a mixture of men and women from Cody and Powell — "are related to a common job-related exposure" at an oilfield company, Billin said, while the other recent case was a Powell man who is an agricultural worker.

“We think it’s basically community spread — spreading it to each other during work,” Billin said Tuesday.

Of the five cases Billin described, none of the people are hospitalized. A COVID-19 patient from Big Horn County was recently hospitalized at Cody Regional Health, he said, but has since been discharged.

Crampton said Tuesday that three of the recent Park County patients had no symptoms at the time they were tested. “They were testing because somebody else around them had symptoms,” he said.

The potential for people to spread the disease without having a fever, cough or other signs of being sick is one reason why health officials continue to urge people to practice social distancing, extra hygiene and wear facial coverings when in close contact with others.

In addition to telling visitors and workers to take precautions, Yellowstone officials have been proactively testing employees to try catching and responding to any outbreak early on.

Through June 10, a total of 387 National Park Service and concession employees in Yellowstone were tested as part of so-called “surveillance testing” — and all of those samples came back negative. Park County health officials are going to start helping to test employees in the eastern portion of the park, Crampton said.

Park County Public Health has also started randomly testing employees at Cody businesses, testing nine volunteers at three businesses last week. Billin said they plan to add three or four more businesses to the so-called “surveillance testing” on Thursday (today).

Health officials have also been monitoring sewage in an effort to see how widely the virus may have spread. Sewage samples collected from Mammoth Hot Springs, Old Faithful and Gardiner, Montana, between May 18-26 showed no sign of COVID-19, though more samples were collected in recent days.

Two tests of the City of Cody’s sewage systems in April and May similarly found no traces of the virus. However, the lab that ran results, Biobat Analytics, has cautioned that the results are not particularly reliable when less than 5% of a municipality’s population is shedding the virus, Billin said.

So while there may actually be some Cody residents infected who weren’t detected in the sampling, “we can be 100% confident, or pretty darn confident, that it’s less than 5%” of the population, Billin told commissioners.

In requesting a variance to loosen the spacing restrictions on local restaurants, the doctor noted that Park County still has a relatively low number of cases — and he pointed to data indicating that the county has adequate testing both underway and available plus enough open hospital beds to handle a possible surge in COVID-19 patients.

As of Tuesday, there were only seven people hospitalized with the disease across the state of Wyoming, Gov. Mark Gordon said at a press conference. However, the governor also said he was sad to see the number of active cases recently spike from fewer than 200 cases to 237.

“Our ability to maintain progress is depending on the good people of Wyoming,” he said, adding that recklessness, carelessness and thoughtlessness could lead to losing ground to the virus.

Gordon said he’s excited to see the Cody Nite Rodeo start up on Saturday — under new restrictions — and noted the plans to hold the annual Cody Stampede Rodeo over the Fourth of July.

“We need Wyoming to be the safe place — not the place that’s spiking on national news, but the place that is safe to go to, where people act responsibly and do the right thing,” the governor said.

Vehicle traffic into Yellowstone National Park between June 11 and June 16 stood at 75% of the same point last year, with the Wyoming entrances at 87%.