CHICAGO (CBS) — A huge group of Catholic pilgrims – numbering in the tens of thousands – is gathered at the Shrine of Our Lady of Guadalupe in Des Plaines.

They’re there for an annual celebration.

READ MORE: Belmont Cragin Carjacking Leads To Fiery Crash, Multiple Other Parked Cars Struck

Father Marco Mercado is director of the Archdiocesan Office of Hispanic Catholics.

“We expect a lot of prayers, a lot of devotions, a lot of families,” he said. “A very nice family environment, a very prayerful one.”

READ MORE: Surveilence Video Shows Moments Leading To The Arrest Of Allan M. Brown, Suspect In Kenosha Police Shooting

As many as a 100,000 faithful could gather today.

The festival honors the Patroness of the Americas. It begins about 4 p.m. and ends with the closing Mass at 8 p.m.

The first celebration of Our Lady of Guadalupe in Des Plaines was held 25 years ago. The event marks the anniversary of the appearance of Our Lady of Guadalupe in 1531 to an Aztec Indian in Mexico, the Daily Herald reported.

MORE NEWS: Police Investigate Bank Robbery In Hyde Park

LISTEN: WBBM Newsradio’s Bob Roberts Reports