ASPEN, Colo.—Prices have gotten so high here that a $1.8 million home late last year was included in an affordable-housing lottery by the Aspen Pitkin County Housing Authority.

That home has yet to sell, but plenty of others in Aspen have. The mountain resort town is part of a real-estate trend playing out in places such as New York’s eastern Long Island shore and in Lake Tahoe, Calif., where home prices have surged as wealthy urbanites look for space and outdoor amenities during the pandemic and while working from home.

Aspen is attracting affluent buyers from both coasts and Texas. July home-sales contracts jumped more than fivefold over that same month a year earlier, a surge that appraiser Jonathan Miller called unprecedented for Aspen in a recent report.