The Park Service, the National Biological Service, and state Fish and Game used two helicopters and more than 30 people in the operation, in which 20 of point's estimated 280 elk were checked for disease and collared for identification.
No elk were injured in the roundup, said workers, who added that they worked with as much precision as possible.
The operation went so: One helicopter, carrying a team of animal-capture specialists from New Zealand, swooped low over an isolated female elk.
A member of the team fired a net from a gun. Another leaped from the aircraft, tackled the animal, and attached a blindfold to calm her down.
blood and fecal samples to test for disease, parasites, and pregnancy.
As one team poked and probed an elk for 15 minutes just southeast of the Pierce Ranch, the animal remained surprisingly calm. When released she leaped up and trotted off to find her herd.
"Of all the methods tried over the years, this is probably the least stressful" on the elk, said John Dell'Osso, acting chief of interpretation for the Point Reyes National Seashore.
In the first two hours, the teams captured and "processed" seven animals. By 1 p.m., all 20 had been collared and tested.
From these studies, wildlife biologists can determine the extent of Johne's disease, a paratuberculosis infection causing diarrhea. They also hope to track individual elk's movement and behavior for the next five to seven years.
To maximize the life of the radio collars, the collars will be activated for 24 hours at a time, and shut off for 24 hours in between.
"We're going to be looking at their reproductive success, looking at their habitat usage, and looking at their offspring," said Bill Shook, resource manager at the National Seashore.
Dr. Howell summarized: "We're trying to find out what's going on with this particular herd. It's kind of like having elk in a giant Petri dish."
Data collected on Tuesday will also form the basis of a comprehensive census on the herd. Park Service officials want to determine what happens when or if the herd reaches its carrying capacity, which the maximum number of elk the 2,600-acre preserve can sustain.
Carrying capacity is currently estimated at 315 to 350 animals. If the herd tops that, Park Service officials fear the lack of food could lead to starvation and a weakened herd.
"It seemed to work very smoothly," said the group's Tule elk coordinator Barbara Pedersen. "Initially, we were not happy with this kind of procedure."
However, she said, the rodeo-style method was far less invasive than the alternative - injection of a chemical sedative. "We would have been more supportive of a corraling method," she added.
Pedersen, who monitored the operation from afar, said she is confident that the Park Service chose the "safest and most effective way to handle the capture."
The 20 collared elk, she said, were "integrating back into their herds and behaving normally."
He said biologists nationwide are often skeptical at first of the company's methods. However, Shook added, once scientists see videos of the work, they are usually won over.
Innes and Company were the first to prove that transporting large animals by dangling them upside down was less traumatic than by cradling their bellies.
Dr. Reg Barrett, a scientist at UC Berkeley watching Tuesday's operation, noted, "They've had a red deer culling program [in New Zealand] for 10 years, so they know more about this kind of thing than anybody in the world."
Nonetheless, after watching the New Zealanders' wild in-flight maneuvers, Ranger Shook said, "I wouldn't want to fly with them."