Cheyenne, Wyo. • A man pets a wild bison on the head. Rescuers pull a treasure seeker from a snowy canyon. A woman taking photos stumbles into scalding water.
Visitors to Yellowstone National Park often leave common sense and situational awareness at home, as those examples in the past year show.
Now, as Yellowstone and other national parks end a two-month shutdown due to the coronavirus, park officials ask visitors to take simple precautions: wash hands, keep a safe distance apart, wear protective face coverings in public.
But it's unclear if tourists will comply or if popular parks known for drawing large crowds will become hot spots.
Memorial Day weekend typically signals the start of the summer tourist season in national parks, when crowds gather shoulder to shoulder at popular scenic spots such as Old Faithful to witness the wonder of a geyser erupting.
As with nature's many other dangers, which in Yellowstone range from sunburn to charging grizzly bears, park officials plan to let the public mostly police itself against disease.
"We can't keep the public away from bison and bears every year at full staffing levels. So the notion that we're going to keep every human being 6 feet apart is ridiculous," Yellowstone Superintendent Cam Sholly said.
Yellowstone, which partially reopened on Monday, has spent $135,000 in recent weeks on sanitizing equipment, finding personal protective gear, modifying boardwalks to spread out foot traffic near thermal features, and posting a "massive amount of signage" to promote hygiene and social distancing.
But Sholly said he has no intention of putting his employees at risk by breaking up every ill-advised crowd.
"It's an easy choice, actually," he said. "That doesn't mean we're not managing it. We're out there."
Other national parks that have reopened include Great Smoky Mountains in Tennessee and North Carolina, where park officials urge visitors to arrive early at popular spots.
"There is plenty of space for visitors to spread out," park spokesperson Dana Soehn said. "But where they aren't, we're not asking our volunteers and employees to enforce it."
At Arizona's Grand Canyon, officials are leaning on an unenforced overnight closure to thin out visitor numbers but not limiting access to the canyon's cliff-hugging trails.
"We're expecting there to be less people on the trails than being open all day," said Grand Canyon spokesperson Lily Daniels. "A lot of it is self-governance."
That's not a good idea, said former Grand Canyon National Park Superintendent Rob Arnberger in an opinion piece Friday in The Arizona Republic.
"It simply defies logic and human behavior to think that people who have traveled long distances to see the canyon will not park and stand in clusters at popular overlooks, or traverse the same trails, bringing them in close contact to each other," Arnberger wrote.
Interior Secretary David Bernhardt, whose oversight includes the National Park Service, will make his thoughts on the matter clear enough: Bernhardt planned to visit the Grand Canyon on Saturday to highlight its reopening.
Zion National Park in southern Utah has partially reopened but shuttle service that helped to reduce car traffic remains shut down, sometimes forcing the entrance to close after parking lots fill up.
Wider use of timed entry, which requires visitors to buy tickets to enter some smaller National Park Service sites at a certain time, could help parks manage crowds during the coronavirus, suggested Kristen Brengel, vice president of government affairs for the National Parks Conservation Association in Washington, D.C.
"A timed entry system could really work to make sure people are spacing out a little more," Brengel said.
For now, only the southern half of Yellowstone is accessible through two entrances in Wyoming. The park opened to daytime use Monday and if all goes well, three other entrances in Montana and the rest of the park — including campgrounds, cabins, stores, restaurants and possibly its grand old lodges — will reopen in phases over the summer.
If too many coronavirus cases associated with the park emerge, Yellowstone can shut down again. The park is working with health officials to coordinate plans and test employees for COVID-19 — with plans to even check for the virus' biological signature in park sewage systems.
"No one's an expert at reopening national parks in a pandemic," Sholly said.
For most people, the new coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia and death.
Early indications of the public taking personal responsibility in Yellowstone aren't encouraging. The photo-taking woman who stumbled into scalding water wasn't even supposed to be in the park — she had sneaked in May 12, six days before the park reopened.
On Wednesday, two days after Yellowstone reopened, a bison knocked over and hurt a woman near Old Faithful.
As has happened in several similar incidents in recent years, the woman got too close to the animal, park officials said.
Felicia Fonseca in Flagstaff, Arizona; Brady McCombs in Salt Lake City; and Travis Loller in Nashville contributed to this report.