Four elk have died at the Hillview Recreation Area dropping the herd size to two animals, a cow and a bull.
Dennis Sohl, Plymouth County Conservation director, said that many deaths in less than a year is unusual.
"We're concerned," he said. "The rate of mortality is more than we can fill with natural reproduction."
That means the conservation board will have to consider purchasing an elk or two to increase the herd size, Sohl explained.
He said the board currently has enough dollars in donations to buy one cow, which cost about $2,000 to grow the herd.
In the future, board members may discuss purchasing a second animal in light of the recent deaths, Sohl said.
During Tuesday's county board of supervisor's meeting, Supervisor Mark Loutsch asked Sohl what led to the deaths of the animals.
Last winter two animals died, one of an infection after being poked by the bull elk's antler, the other from pneumonia, Sohl said.
The other two elk died a couple weeks ago, following a "totally unexpected" calf born late in the season. Elk are usually born around June, Sohl said.
The big bull elk, already in rut, or the mating period, would not let the newborn calf nurse causing its death, he explained.
Then the cow died from infection because it was not able to expel the after-birth, Sohl said.
He explained that although the United States Department of Agriculture classifies elk as livestock, they are still wild animals.
"We cannot get close to them to monitor their individual health very well," Sohl said.