Many of the features of this Cougar Mountain pool complex were made from natural rock molds.

WHEN JOE HAENER moved into his home at the top of Issaquah's Cougar Mountain in 1995, he sat outside with a glass of wine, pondered the yard - a steep slope of mostly dead, clumpy grass - and imagined what could be: a useable yard, a pool, a place for children to play, all while respecting the natural landscape.

What Haener pictured, Casey Castillo brought to life. And more.

Today the terraced, landscaped hillside features a par-2 golf pitching green, two sunning patios, a 30-foot pool that curves around a fir tree, a grotto with inner and outer waterfalls, and a 25-foot pool slide that looks like a cutout Ponderosa pine.

"It's perfect," says Haener.

Castillo is co-owner of Natural Creations (www.ncinc.com), a Renton design and construction company that uses rock, hand-carved artificial rock and natural rock molds to create unique home and commercial installations. At Haener's residence, Castillo began by building a 100-foot-long, 9-foot-high concrete retaining wall at the base of the slope, to prevent erosion. Workers pushed the hill inwards, excavated for the pool on the lower terrace, then backfilled to create four other shotcrete walls, also cobbled with tumbled sandstone.

Entering from the driveway, visitors first encounter a stone inset with a "Haener Heights Country Club" plaque, which indicates the golf hole is 25 yards (24 for ladies). Six steps down from the tee, the fairway doubles as playground and entry point for the pool slide. Seventeen more steps is poolside; another patio sits between levels to the rear.

Tumbled sandstone is used around the pool edges as well, but the steps, arched grotto and other major stone-like features are made from some of Castillo's 200 trademark molds. He creates them by hiking into arid climates to find indigenous samples free of moss, applying latex rubber, and letting it dry for three weeks before removing (without damaging the environment). Back at his Renton factory, Castillo sprays into the mold a face coat with pigments, followed by a backup coat of fiberglass mixed with cement. For larger structures, he casts rebar into the backs of the panels.

The result is museum-quality faux rock one-tenth the weight of the real thing. The arched grotto entry comes from molds Castillo took in Chelan Gorge. Poolside is 4-inch-thick Canyon Floor decking. The steel and concrete slide's remarkably detailed exterior "bark" comes from a mold of a fallen Ponderosa pine he saw while working on the swimming pool and spa at the Sleeping Lady Retreat and Conference Center in Leavenworth.

The grotto envelopes a 24-inch swim-out that has its own heat source and is shallow enough that the Haener children can begin to learn to swim there. Built into the back wall are a stone champagne bucket and cup holders; the interior waterfall is designed so it won't drip into the cups. Plants and planter pockets abound. "When you're designing you want to design with all the elements in mind and not just how much rock work you can show," Castillo says.

The pool, 3 to 6 feet deep, has fiber-optic lighting in eight colors for night effect. A light on the front of the grotto illuminates the outer waterfall. To keep heating costs down, Haener had the pool interior painted a dark color to help absorb the sun's heat, and when the pool's not in use he covers it with a custom plastic bubbletop.

The six-month project, which cost about $200,000 including landscaping, was finished despite a big snowstorm that left the Haeners without power for days. So it's no coincidence that underneath it all, behind that initial retaining wall in a cave for pool equipment, is a generator that can power not only the pool but the entire house.

Molly Martin is assistant editor of Pacific Northwest magazine. She can be reached at 206-464-8243, by e-mailing mmartin@seattletimes.com or writing P.O. Box 70, Seattle, WA 98111.