Details from their YouTube page:

Virtually everything you are about to see happened on a single day in the United States of America, July 4th, 2017.

Over 10,000 generous and creative people submitted footage – in addition to our 92 professional crews. We filmed in all fifty states, Puerto Rico and D.C. and captured a portrait of this country that is absolutely beautiful, challenging and unforgettable. A very small selection of that footage you see here.

The rest will be part of the documentary film, A DAY IN THE LIFE OF AMERICA (directed by Jared Leto), that is a companion piece to our brand new album. The album.

The film. The tour. Coming #soon. Thirty Seconds To Mars.

Music video by Thirty Seconds To Mars performing Walk On Water. (C) 2017 Thirty Seconds to Mars under exclusive license to Interscope Records http://vevo.ly/cGu2fJ