PORTLAND, Ore., Feb. 18 (UPI) -- Oregon's only moose herd appears to be thriving in the northeast mountains this winter, state wildlife biologist Pat Matthews said.

He said the deep snow and occasional sub zero temperatures are to the the animals' liking, The (Portland) Oregonian reported Monday.

"In the winter when it gets above 23 degrees, they start looking to cool themselves down," he said. "In the summer, anything above 60 degrees is too warm for them."

Moose watchers may even be able to see the elusive creatures this spring and summer by floating the Grande Ronde River between Minam and Troy or driving the now snow-covered U.S. Forest Service roads.

"They are very secretive and solitary animals, and they show up when they show up," Matthews said. "It took us a long time before we started seeing them."

The assistant district wildlife biologist with the Oregon Department of Fish and Wildlife said the agency estimates that the population numbers about 38, but the herd could include up to 60 animals.