Which 1999 independent horror film was shot in a found-footage style and created a viral marketing campaign?

The 1999 independent horror film shot in a found-footage style and promoted through a pioneering viral campaign is The Blair Witch Project.

Written, directed, and edited by Daniel Myrick and Eduardo Sánchez, the film presents itself as recovered recordings made by three student filmmakers investigating the Blair Witch legend near Burkittsville, Maryland. Heather Donahue, Joshua Leonard, and Michael C. Williams played fictionalized versions of themselves, helping the improvised performances feel like documentary footage. Most of the filming occurred in Maryland's Seneca Creek State Park, and principal photography lasted only eight days.

The marketing campaign deliberately blurred fiction and reality. The film's website used faux police reports and interviews, while promotional materials described the actors as missing or deceased. This approach encouraged early internet audiences to debate whether the footage was genuine. The film premiered at Sundance in January 1999, expanded nationwide that July, and became a major independent hit, earning nearly $250 million worldwide. Paranormal Activity later used a similar found-footage framework, but it was released in 2007. The Blair Witch Project helped establish internet-driven movie promotion as a powerful mainstream strategy.