MORRISON, Colo. — Saturday night’s Lumineers concert at Red Rocks Amphitheatre was the sort of iconic Colorado show that no band could plan for — nor would any want to.

With floodwaters still churning away in much of the state, the night was at once a victory lap for the Denver folk band and a bittersweet swan song for summer 2013. There are still a handful of events scheduled at Red Rocks this year, but with chilly temperatures and random cloudbursts hovering over the venue, it was clear that outdoor concert season is just about over.

The Lumineers happily took their place in Colorado music lore, at one point hiking up the Red Rocks steps to perform from the middle of the 9,500-person crowd. But frontman Wesley Schultz and company also seemed humble, thanking everyone for braving the weather and passing the hat (actually, a large plastic water container) for donations to the flood relief effort.

The most symbolic moment of the night came when opening act Langhorne Slim and the Law joined the Lumineers onstage for a rowdy version of the Violent Femmes’ “American Music.” For a pair of bands who are each a melting pot of American musical influences, it was pretty close to perfect.

Earlier, L.A. rockers Family of the Year showed off their catalog beyond the radio hit “Hero,” while Denver’s Paper Bird finally seemed to take flight, their baroque pop sound resonating with Lumineers fans.