A booming Twin Cities megachurch has added the former McNally Smith College of Music in downtown St. Paul to its list of worship locations.

River Valley Church, which began in Apple Valley and now hosts services at eight sites in Minnesota and one in Africa, will hold its first St. Paul services at 30 East 10th St. this Sunday.

A church spokesman said River Valley was looking to expand into St. Paul and was struggling to find the right venue about the same time that McNally Smith announced last December that it was closing. The church signed a one-year lease and will share lobby and auditorium space with the building’s other tenant, History Theatre. Church officials say they’re hoping to attract 400 to 500 worshipers at two services Sunday.

The former McNally auditorium holds about 300 people.

The building was once home to the Science Museum of Minnesota, which moved to new facilities overlooking downtown St. Paul’s riverfront in 1999. A group of investors bought the McNally building for $4.5 million in June. (The Church of Scientology started calling another former Science Museum building home after purchasing the property across Wabasha Street in 2007.)

River Valley, founded in 1995 in Apple Valley with 13 people at the first service, on its website says it is “one church, multiple locations.” Other sites are in Minneapolis, Eagan, Woodbury, Shakopee, Faribault, Eden Prairie, Minnetrista and Swaziland. In 2014, a periodical for evangelical Christian churches named River Valley the 23rd fastest-growing church in the country.

Its Minneapolis campus, located in the North Loop, started with about 300 people attending services, said founder and Lead Pastor Rob Ketterling. More than 1,000 are expected to attend four services there Sunday.

“St. Paul came up as a place that could use another church, another new church, that could join the great churches that were already there,” Ketterling said. “We’d had success in Minneapolis and we wanted to try to replicate it in St. Paul.”

River Valley has sought to use “reclaimed space” in creating its church campuses, Ketterling said. The original church in Apple Valley once was a Walmart shipping center. The site in Eden Prairie had been a science lab.

As a multisite church, River Valley relies on video. Ketterling delivers his weekly sermon in Apple Valley, then video of that message is shared at campuses across the state.