The creators of TV's "South Park" may have killed Kenny in the show, but not too many trees died when they built their environmentally friendly mansion in western Colorado.

The $5 million Steamboat Springs home belonging to Trey Parker and Matt Stone features ceilings made of Douglas fir timbers salvaged from a rail trestle that once spanned Great Salt Lake.

The home also uses recycled carpet and in-floor, radiant heating.

The timber-frame home on two acres overlooks the Steamboat Ski Area.

"They can come here and get their dose of nature," designer Michael Rath told the Steamboat Pilot & Today newspaper.

The creators agreed to open the doors to their environmental mansion but were not interviewed for the story.

The home built in 2007 blends western design with Japanese accents. It has two dining rooms. One has views of a mountain valley, the other of an aspen grove.

In the rear of the property, at the end of a winding stone walkway, is a Japanese tea house with sliding screens as walls, and tatami mats on the floor.

Rath said the blend of east and west earned the retreat a profile in an upcoming edition of Architectural Digest.

The "South Park" creators visited Steamboat Springs as children and wanted to build a getaway there, he said.

Stone and Parker have master bedroom suites on opposite ends of the mansion that they use for vacations or to entertain family and friends.

"I think what this house means to Matt and Trey is Colorado roots," Rath said.

The Routt County Assessor's Office said the land was purchased in 2002 for about $1.4 million. The main residence, tea house and land improvements have raised the value, for assessment purposes, to just less than $5 million.