KATHMANDU (Reuters) - Fifteen Nepali artists were closeted for a month with a heap of 1.5 metric tons (1.7 tons) of trash picked up from Mount Everest. When they emerged, they had transformed the litter into art.

The 75 sculptures, including one of a yak and another of wind chimes, were made from empty oxygen bottles, gas canisters, food cans, torn tents, ropes, crampons, boots, plates, twisted aluminum ladders and torn plastic bags dumped by climbers over decades on the slopes of the world's highest mountain.

Kripa Rana Shahi, director of art group Da Mind Tree, said the sculpting - and a resulting recent exhibition in the Nepali capital of Kathmandu - was aimed at spreading awareness about keeping Mount Everest clean.

"Everest is our crown jewel in the world," Shahi said. "We should not take it for granted. The amount of trash there is damaging our pride."

Nearly 4,000 people have climbed the 8,850 meter-high (29,035 feet) Mount Everest, many of them several times, since it was first scaled by New Zealander Sir Edmund Hillary and Tenzing Norgay Sherpa in 1953.

Although climbers need to deposit $4,000 with the government, which is refunded only after they provide proof of having brought the garbage generated by them from the mountain, activists say effective monitoring is difficult.

Climbers returning from the mountain say its slopes are littered with trash which is buried under the snow during the winter and comes out in the summer when the snow melts.

The trash used in the art works was picked up from the mountain by Sherpa climbers in 2011 and earlier this year and carried down by porters and trains of long-haired yaks.

The yaks were commemorated in one work. For another, empty oxygen cylinders were mounted on a metal frame to make Buddhist prayer wheels.

Another, by wall painter Krishna Bahadur Thing, is a Tibetan mandala painting showing the location of Mount Everest in the universe - made by sticking yellow, blue and white pieces of discarded beer, food cans and other metals on a round board.

Visitors said they were amazed at the way waste products were turned into useful items.

"It shows that anything can be utilized in an artistic way and nothing goes to waste in art," said 18-year-old fine arts student Siddhartha Pudasaini.

The art is on sale for prices from $15 to $2,300, with part of the proceeds going to the artists and the rest to the Everest Summiteers' Association (ESA), which sponsored the collection of garbage from the mountain, organizers said.

"Garbage on Everest is shameful. We are trying to turn it into gold here," ESA chief Wangchu Sherpa told Reuters.

(Reporting by Gopal Sharma, editing by Elaine Lies)