Experimental films are rare in this festival, so it’s a treat to find in the Documentary Competition this lyrical 16mm reportage co-directed by J.P. Sniadecki and Joshua Bonnetta. In 2014’s fest Sniadecki, who teaches film at Northwestern University, screened “The Iron Ministry,” a more conventional documentary about China’s train passengers. This time the setting is the U.S. border. The filmmakers record traces left by northbound Mexicans, typically night travelers. Despite its maritime title (“mar” is Spanish for “sea”), the film is a landscape study of the Sonoran Desert, with its forest fires and thunder storms. The eclectic soundtrack has off-camera testimony, a reading of a 1692 poem by a Mexico City nun, and the 1954 song “Johnny Guitar.” 6 p.m. Oct. 24; 1:15 p.m. Oct. 25.
The Chicago International Film Festival continues through Thursday at AMC River East 21, 322 E. Illinois.