Eco Logic? 

Obsessive people who avoid becoming stalkers or sociopaths often contribute significantly to the greater good. They can radiate incredible energy and creativity - and this is certainly the case with Andy Goldsworthy. The British sculptor's singular drive provides the focus for Rivers and Tides, a documentary opening this weekend at the Savoy Theater in Montpelier.

Thomas Reidelsheimer, the movie's German director, cinematographer and editor, spent a year following Golds- worthy all over the world. The celebrated "environmental artist" uses the planet's detritus as his medium. The projects he painstakingly crafts on camera include a web of twigs, a chain of leaves stitched together and floating in water, a circular hive of driftwood and an egg-shaped cairn of stones.

For the most part, these beautiful outdoor assemblages are meant to be temporary. They tend to be destroyed by gravity, heat, wind or rain. Goldsworthy's goal is always to devise "a tangible thing that is here and then gone." His specialty is ephemera. The rising sun first illuminates his constructed arch of icicles, then relentlessly melts it. This process delights Goldsworthy, who loves watching the "earthworks" slowly succumb to the elements. "These are moments that I just live for," he confesses.

Spontaneity plays a big role in each effort. At their home in rural Scotland, Goldsworthy's wife asks: "What are you going to make today?" He has no real answer for her. However, Reidelsheimer continually coaxes him to explain his process and nuanced connection to nature. "We misread the landscape when we think of it as pretty," Goldsworthy says at one point, while fashioning a mat on the ground from toxic bracken. "There is a darker side."

Environmental activism's darker side comes across in Betraying Reason, a Canadian feature that screened at the recently concluded Montréal World Film Festival. Writer-director Lili Schad, now a Vancouver resident, grew up on a farm near Toronto and lived in Vermont during the early 1990s.

At the time, she had decided to take a year off from a promising but draining business career. "I moved to a house in Moretown," recalls Schad, now 43. "Well, a shack with no toilet."

She was no impoverished waif, though. In 1953, Schad's father, Robert, founded Husky Injection Moulding Systems and invented the snowmobile. You might say powder is in his daughter's blood. Her ties in the Green Mountain State were mostly on the slopes. "I teamed up with my old skiing rat pack," she says, referring to friendships formed during visits to the Mad River Valley every winter.

Through one of those pals, "local hero" Johnny Eagan, she hooked up with Warren Miller of ski-movie fame. When he was at Sugarbush, Schad signed on as his still photographer. "We traveled everywhere doing these documentaries," she remembers. "Yugoslavia, Turkey, Roman-ia, Russia."

That sojourn in the former Soviet Union convinced Schad to return there in 1993 to shoot her own sports doc, starring Eagan and other noted Vermont skiers. Fire and Ice depicts their expedition to climb up and ski down an active volcano in Kamchatka - a remote region where no Westerners had ever ventured, according to Schad. "We were on the cusp of the extreme-skiing movement," she adds.

After Fire and Ice toured the festival circuit and aired on TV, Schad relocated to San Francisco to hone her filmmaking skills. She worked on social-issue documentaries. Let the River Run is a 1998 ecological tour with the late David Brower, founder of the Sierra Club. The same year, Mavericks captured the irresistible lure of surfing a monster wave in Half Moon Bay, California.

Betraying Reason is the fateful story of a young man, Reason Boles, who has a cabin on family land where loggers are cutting down the old-growth trees. He tries to sabotage their pillage of the woods, finding inspiration in Black Bart, the legendary bandit responsible for robbing more than two dozen Wells Fargo stagecoaches with an empty gun in the 1870s. When a pretty woman and her little daughter become stranded on his property, Reason's loner lifestyle is disrupted.

Schad's next planned venture, Into the Forest, is based on the popular 1996 Jean Hegland novel. It's a post-apocalyptic tale about two teenage sisters who survive despite drought, fire, famine and plague raging elsewhere.

"As the world crumbles around them," Schad says, "they learn to build a new civilization." OK, but will they be able to ski?