Outdoor leisure retailer REI has announced the death of Mary Anderson, one of its co-founders, at the age of 107.

Ms Anderson, who died on 27 March, was a keen mountaineer who started the consumer co-op in 1938, alongside her husband Lloyd and 21 of their friends, so they could buy good quality, affordable climbing gear in bulk from Europe.

REI has since grown from its Seattle base into the largest consumer owned retail co-op in the US, with around about 6.3 million active members, more than 140 stores and 12,000 employees.

The Andersons came up with the idea in 1935, when they grew tired of buying overpriced, imitation Austrian ice axes. Using Mary’s German language skills, they ordered the real thing by catalogue from Austria.

When their climbing friends wanted to do the same, the couple realised they could enjoy the economies of bulk-buying if they formed a co-op.

The initial group came together with a $1 lifetime membership fee, with Ms Anderson holding membership card No.2. The retail operation, funded by a $30 loan from the Andersons, started out from humble origins: stocked on a shelf in a local co-op store, with the good stored in the couple’s attic.

Operating from their Seattle home, Mary would stitch tents together before Lloyd sprayed them with waterproofing.

An REI blog says: “Since day one, when Lloyd and Mary were joined by the original 21 members, our co-op has been rooted in our people – in the folks who ask more of their gear and of themselves, the stewards who care to preserving the land we play on, and in the adventurers who want to go farther.

“As we continue to grow and evolve, and even as the world around us continues to do the same, we remember how far we’ve come since our first ice axe, our first shelf, and our first members, and we remain committed to doing right by Lloyd and Mary’s vision of a co-op that puts members first, until the last bell rings.”

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Paying tribute to Mary Anderson, an REI statement said: “Mary’s legacy is deeply engrained in REI and her contributions to the outdoor community extend far beyond the co-op.

“REI and our employees are grateful to the Andersons for their dedication to REI and the incredible foundation they established. It is our honour to carry on their commitment more than 75 years later and beyond.”

Born Mary Gaiser in the Yakima Valley region of Washington on 7 December, 1909, she was a schoolteacher before REI became successful. She retired in 1968 but kept close links to the organisation.

On her 100th birthday, Mary visited REI to share stories of her life in the mountains, and the co-op established a legacy grant in her name to encourage young people to enjoy the outdoors.

Tom Vogl, a former head of marketing at REI who also worked with Mary on The Mountaineers, a non-profit outdoors community, said she was “a pioneer”.

He told a radio interview: “She joked that she and Lloyd never really intended to start up a store. They really just wanted to try to make it easier for people to get outdoors and experience the wondrous wilderness that surrounds us here in the Pacific Northwest.

“I am thoroughly convinced that one of the key reasons why Mary lived to 107 years old is because she lived a really great life that was inspired by the outdoors.”

Lloyd Anderson died in 2000 and the couple are survived by a daughter, Sue Anderson, and two grandsons. Another daughter, Ruth, died before her.