Montana is on the cusp of joining a growing national trend in overhauling single-family zoning laws to increase multifamily density, create more affordable urban housing and help quell suburban sprawl.

The Big Sky state’s House of Representatives passed three bills Thursday by large margins, sending them to Gov. Greg Gianforte for his signature.

The measure shows how housing affordability touches even the least populous states in the nation. Montana had fewer than 1.2 million residents in 2022, according to the latest Census Bureau data, less than some large U.S. cities.

“The pro-housing reforms supported by our legislature will protect Montana’s rural areas and ranch land from California-style urban sprawl by providing more freedom to landowners to build affordable starter homes in cities,” Kendall Cotton, CEO of Montana nonprofit free-market advocacy group The Frontier Institute, told CoStar News in a Twitter message.

Once law, Montana would join the wave of efforts around the country to shake off decades-old zoning that reserved large sections of cities for single-family homes. The zoning prevents duplexes, triplexes and fourplexes, the so-called missing middle, as well as apartments from being built.

Minneapolis, California and Oregon have taken steps to make zoning less restrictive. Colorado’s legislature is considering a similar overhaul to zoning regulations. Arlington County, Virginia, and St. Petersburg, Florida, recently passed ordinances to allow a moderate increase in housing density in urban areas.

One of the bills Montana lawmakers passed would allow duplexes in urban areas. Triplexes and quadraplexes were cut from the bill during a committee process to address concerns from opponents that the greater density would put too much pressure on existing infrastructure.

Proponents of the bill argued it would revive construction of missing middle housing, which is between single-family homes and high-density, to provide more affordable housing and increase accessibility to housing. Students at the state’s largest universities in Bozeman and Missoula could move closer to campus instead of living in temporary housing such as recreational vehicles.

Another recently passed Montana bill legalizes multifamily housing and mixed-used development in Montana cities with a population of more than 7,000. That would include Billings and Bozeman — where Montana State University is located — and Missoula where the University of Montana is located, as well as the state capital of Helena and Great Falls.

A third bill would ensure cities are planning for future housing needs based on population growth. It includes altering the planning process to have public input at the front end instead of throughout the process. Cotton said in a Twitter post that the bill eliminates unnecessary public hearings being taken over by not-in-my-backyard efforts.

The Montana League of Cities and Towns opposed the first two bills while supporting the third bill, which it helped write. That one preserves the right of cities to have a say in planning what they think is best for themselves, the organization said during the bill’s debate period.

Kelly Lynch, executive director of the Montana League of Cities and Towns, said during a committee meeting in late March that the duplex bill “forced zoning” and that current zoning protects “private property rights” of single-family homeowners so they know a fourplex won’t be built next door.

Cotton with The Frontier Institute said during the hearing that current single-family zoning in many Montana cities looks similar to Los Angeles in terms of the percentage of parcels zoned for single-family homes. “If our cities look like L.A., they are going to grow like L.A.,” he said.