Their six-week spring tour was largely sold out – even at Boston’s nearly 2,000-capacity Avalon – and frontman Colin Meloy played to packed houses in the cities lucky enough to get a spot on his January solo mini-tour.

So what’s a band to do? Book its most ambitious tour yet, of course.

This September, the Portland, Ore.-based indie rockers will kick off a two-month nationwide tour, called – we kid you not – “The Flight of the Mistle Thrushes.” The schedule includes double gigs at San Francisco’s Fillmore, New York City’s Webster Hall, Los Angeles’ Music Box at the Fonda, Chicago’s Metro and the Big Easy in Boise, Idaho.

Fans in the group’s Pacific Northwest home can catch some pre-tour gigs in August, including shows with the Violent Femmes and Death Cab For Cutie.

The Decemberists will make a trip to NYC’s SummerStage in Central Park August 18 and play Seattle’s Bumbershoot Festival main stage September 5 before officially starting the tour in San Francisco September 11.

The packed itinerary includes two Texas dates with Built to Spill – one of them a co-headliner in Houston.

Sons and Daughters will open on the first half of the tour, with Cass McCombs taking over support duties from October 5 through the end of the month.

The tour wraps October 30 at the Voodoo Festival in New Orleans’ City Park.