The number of local cases of COVID-19 continued to rise this week, with 11 positive tests announced Tuesday and five more on Wednesday.

Tuesday’s total represented the largest single-day increase to date. However, Park County Public Health Nurse Manager Bill Crampton said most of those cases appeared to be tied to previously detected infections rather than representing a new outbreak.

“A lot of it is in families or extended families that we’ve already been working with, and a couple of businesses that we already were aware of,” Crampton said Tuesday afternoon. “But … there’s three or four of them that are brand new.”

Most of Park County’s recent cases have come from “larger gatherings such as weddings, retirements and at eating and drinking establishments,” health officials said Monday. While there have not been specific details released about all of the cases, some have involved employees at a North Fork resort and at least two Powell bars. A Park County road and bridge worker is also believed to have been infected, Crampton said.

The county reached a new high of 43 “active” cases of the respiratory disease on Wednesday: 36 confirmed and seven “probable” cases — where someone has had close contact with an infected person and is showing symptoms of COVID-19, but hasn’t been tested.

None of the people infected in Park County are hospitalized and have been recovering on their own.

Amid the rise in cases, Park County Health Officer Dr. Aaron Billin encouraged residents to take precautions over the Fourth of July holiday. He specifically recommended that those who are the most vulnerable to the virus skip out on this week’s Cody Stampede Parade and other events with big crowds.

“Although outdoor activities are safer than indoor activities, July 4th activities carry [an] increased risk with the recent spread in Park County,” Billin wrote in a Facebook post. “Those who are sick, over 65, have underlying health problems, or have close contact with someone who is at risk should avoid large gatherings and consider celebrating the 4th in another way.”

The recent cases have generally been among younger adults, Crampton said, who are at a lower risk of becoming seriously ill from the novel coronavirus. However, health officials’ bigger concern is that those people could infect senior citizens or those with underlying health conditions, who are at much greater risk.

As an example of the threat the virus poses to vulnerable populations, when 16 residents at a Worland nursing home in Washakie County became infected with COVID-19 last month, four of them died.

Park County has had 54 confirmed or probable cases since June 11 (with 11 official recoveries), after having only two in the nearly three months before that.

Also on Tuesday, six new cases were reported in neighboring Big Horn County. Health officials there said all of the infections were within a family. Together, Park and Big Horn counties accounted for 17 of the 33 confirmed cases reported across Wyoming on Tuesday.

Between confirmed and probable cases, the state hit a new high of 375 active cases on Wednesday, according to data compiled by the Casper Star-Tribune. Nine people were hospitalized with the disease in the state on Wednesday, according to state data. That’s down from a peak of 23 hospitalizations in April.

Meanwhile, officials in Yellowstone National Park announced Tuesday that 577 tests conducted on park employees through June 18 had turned up no confirmed cases of COVID-19; another 162 tests are pending.

The disease is “easily spread when in close contact with others,” Park County health officials say, most often transmitted by respiratory droplets when infected people cough, sneeze or talk. That’s why health experts recommend people stay at least 6 feet apart and wear a facial covering in public settings.

Billin said a growing body of scientific studies show that wearing facial coverings is “the single most effective public health measure that can be employed” to slow the spread of COVID-19, with broad mask usage potentially reducing transmission by 40%.

The Centers for Disease Control and Prevention says it’s unclear as to when a person becomes infectious, but notes reports of people spreading the virus without ever showing symptoms. The World Health Organization says the virus is mainly spread once someone has symptoms, such as a cough.

“We have tried like the devil to tell folks, ‘Look, don’t work when you’re sick,’” Crampton said. “And yet, either because it’s a paycheck or it’s personal pride or whatever, there are still people going to work with fevers, and, you know, that’s got to stop.”

Park County health officials have been issuing formal quarantine orders that direct people who’ve been in close contact with an infected person to stay home. Crampton said his department had issued more than 75 such orders as of Sunday. (If a person tests positive, they are issued a more restrictive isolation order.)

He said the few people and businesses who are refusing to follow the orders and guidelines and work with health officials are putting the community at risk.

“If we start getting more cases and businesses are involved, you know, the governor and the state health officer may have to pull back the reins” and reinstate restrictions, Crampton cautioned. That, he said, could worsen the financial problems that businesses faced when the public health orders were first put in place — “and we don’t want to go there.”