An estate in one Aspen family for 70 years now searches for new ownership. The 12-acre contemporary at 700 Nell Erickson Road is on the market for $17.95 million after Paula Zurcher, 90, decided to sell. Zurcher is the daughter of Walter and Elizabeth Paepcke, who together in 1946 contributed to the development of downtown Aspen by founding The Aspen Skiing Company and created The Aspen Institute — now an international nonprofit think tank — three years later. The Paepcke’s business endeavors in Aspen spawned after the family found the 400-acre gem 10 minutes from downtown during a mountain hike.