If the whole “spring cleaning” shtick doesn’t have you running to tidy up your attic, consider another motivation: money. Those baseball cards collecting dust could be worth a fortune. Just ask the folks at Castle Rock–based Mile High Card Company, which has been selling some of the country’s rarest sports cards and memorabilia for more than two decades. Owner Brian Drent began hawking cards as a teenager to make some quick cash and eventually created one of the nation’s foremost online auction houses, with sales regularly generating millions of dollars a year. Mile High’s most recent auction hadn’t ended by press time, but the selection featured several high-end cards, including a 1932 U.S. Caramel Babe Ruth (the same card in a similar condition went for $83,650 in 2016) and a 1952 Topps Mickey Mantle. One of the most sought-after cards from any era, it was expected to fetch more than $30,000. Still, that’s small-time compared to the anonymous buyer who dropped $523,000 on 19 unopened packs of 1948 Bowman baseball cards, in their original box, during a Mile High auction this past June. And just where were those precious packs discovered? Inside a Stroh’s beer case in a Tennessee attic, where they’d been untouched for more than 50 years.

Photo Courtesy of Mile High Card Company
Photo Photo Courtesy of Mile High Card Company
Photo Courtesy of Mile High Card Company
Photo Courtesy of Mile High Card Company