HARRISBURG, Pa. — The search by the booming North American population of Amish for affordable, fertile farmland has produced settlements in 28 states and Ontario – and has even led parties to scout recently for suitable properties in Alaska and Mexico.

A new study estimates the number of Amish has increased nearly 10 percent in the past two years alone, to a total population of 249,000, compared with about 227,000 in 2008. That figure was just 124,000 in 1992. Nearly all Amish descended from a group of about 5,000 in the early 20th century.

The study by the Young Center for Anabaptist and Pietist Studies at Elizabethtown College in Elizabethtown, Pa., found that about two-thirds of Amish still live in the traditional strongholds of Pennsylvania, Ohio and Indiana, but that they continue to spread west, particularly into the Midwestern corn belt.

Farmland in Lancaster County, Pa., can cost $15,000 an acre, compared with $2,000 or $3,000 per acre elsewhere.

"They are sort of challenging some of the mainstream assumptions about progress and how you achieve the good life and happiness," said Elizabethtown professor Don Kraybill, the study's director. "They're not merely surviving; they're thriving, and growing at this very rapid rate."