ANCHORAGE—On the edge of this northern outpost an unfamiliar sight is emerging: twin minarets. Alaska's small but growing Muslim community is building the state's first newly constructed mosque.

"This is our future," said Osama Obeidi, one of the Muslim-Americans leading the building effort for the Islamic Community Center of Anchorage. "We have second-generation Alaskans now, and new people coming all the time. We need a place to call home."

The 15,000-square-foot mosque, taking shape near a Sons of Norway Viking Hall, will eventually include a Sunday school and a community center. Heated floors will make worship in the bitter winters more comfortable.

The mosque is perhaps the clearest sign yet that Islam in the U.S. is rapidly pushing beyond traditional population centers such as Detroit and Los Angeles. As the number of American Muslims grows through both immigration and higher-than-average birthrates, domes and minarets are sprouting in areas as varied as the eastern mountains of Kentucky and Louisiana's parishes.

The building boom reflects American Muslims' desire for a sense of permanence as their religion shifts from one mainly imported by immigrants to one practiced by their American-born children and grandchildren, Muslim leaders say.