Staff at Acadia National Park in Maine say they handled unprecedented number of emergency calls on July 5, the same day the park smashed a single-day visitation record.
That Friday, 35,000 people visited — a 15% increase over the previous single-day record set several years earlier.
"Anyone that was here that day could certainly feel it," said Laura Cohen, acting chief of interpretation for the park.
In-depth news coverage of the Greater Boston Area.
The surge of people caused miles-long traffic jams on Ocean Drive and closed Cadillac Mountain's summit road multiple times.
At one point, according to Cohen, "600 cars were competing for 157 spots at one time."
A more serious strain was the high number of calls going in and out of the park dispatch center.
"At one point, the park staff were responding to four different calls for rescue or emergency at one time," said Cohen. "This really stretched the staff."
Certain emergencies required more help to ensure a safe outcome.
One of those was a multi-hour helicopter rescue, in which a 69-year-old woman who went unconscious after suffering heatstroke was pulled off a rocky trail.
Forest Service Chief Pilot John Crowley helped set up the operation.
"They're very conservative about when they call the helicopter," said Crowley.
But carrying someone on the ground for miles down a steep trail could have required dozens of people to help and taken much longer
Using the helicopter, paramedics and forest rangers were able to lift the woman out by carrying her to safety on the end of a long tether attached to the helicopter with a fraction of that number of people.
"Getting 40 people together quickly is difficult," said Crowley. "Something like heatstroke, you want to get that patient to the next level of care quickly."
Crowley says overcrowding in Acadia does not necessarily affect his rescues there.
He said strained staff can pull resources in many different directions, something Cohen confirmed.
She also said a solution to making the park easier to get around and more manageable is a new reservation and transportation system meant to regulate the number of individual cars that can park at some of Acadia's most popular sites like Sand Beach.
That system is set to take effect in 2020.