Bill Morrison, whose extraordinary documentary Decasia (2002) turned decomposing film stock into the stuff of avante-garde reverie, returns with another staggering journey into the past. In 1978 a construction crew in Dawson City, Yukon, uncovered hundreds of reels of silent film that were used as landfill after a local theater switched over to talkies in the 1930s. Drawing on these materials as well as archival photos and other movie clips, Morrison reconstructs the history of the frontier town from its gold-rush heyday to the present, even as he connects it to the emergence of the American cinema. The movie honors the silent-film aesthetic with a majestic score and the narration in onscreen titles, though composer Alex Somers cuts loose with a little electronic noise whenever Morrison presents one of his abstract studies in peeling emulsion. Included is rare footage of the Chicago “Black Sox” playing the infamous 1919 World Series.