On a subfreezing morning at the Woodland Park Zoo this week, the orangutans were huddled in their heated indoor area while a zoo employee broke up the ice that at one point had been a series of rivers and waterfalls.

The elephants, tapirs and sloth bears were nowhere to be seen as visitors in thick coats and gloves walked by empty outdoor enclosures.

About the only animals that seemed to be enjoying this week's cold snap were the relative locals – the animals exhibited in the zoo's Northern Trail.

Wolves darted between trees on frozen patches of grass and two grizzly bears inspected the edge of a pond covered in small floating islands of ice.

"The one zone we have here where every single animal is at home this time of year is the Northern Trail," said Martin Ramirez, Woodland Park Zoo animal curator.

In addition to the Northern Trail animals, the zoo's snow leopards are also loving the winter weather, Ramirez said.

He said many of the zoo's outdoor animals have access to or are confined to heated indoor areas this time of year.

The hardest part about caring for the animals in subfreezing weather is providing unfrozen drinking water to each enclosure and keeping the pipes from bursting, he said.

Though the animals obviously come first, one of the biggest hurdles of this time of year is keeping the zoo's guests happy, Ramierez said.

"The good thing about this place is we have other options for our visitors," he said.

The tropical rain forest, nocturnal and reptile houses, and the indoor areas of the orangutan and gorilla habitats satisfy the customers, he said.

Employees at the zoo's ticket booth said they actually get more complaints about visitors not being able to see the animals during the summer months.

During the winter, there are less people around, encouraging the animals to make themselves more visible, they said.