It's raining women — entrepreneurs, that is.

Across America, the number of women-owned businesses ismultiplying at a faster rate than the number of businesses owned bymen, according to new research.

Over the past 15 years, when the number of businesses in theU.S. increased by 34 percent, the number of women-owned companiesjumped by 50 percent — a rate 1.5 times the national average, a recentreport commissioned by American Express OPEN found. Nationally,there are now 8.3 million women who own their own firms.

And while much attention is paid to women-owned companies instartup hubs likeSilicon Valley and its east-coastcousin, Silicon Alley, those regions aren't the oneswith the fastest-growing rates of female entrepreneurship.

Turns out, when it comes to areas of the country with thefastest-growing number of women-owned firms, rural statesdominate.

How come? Alice Bredin, small business adviser to AmericanExpress OPEN, noted women in remote areas hit hard by the recessioncan't just drive down the road for work if they or theirhousehold's primary breadwinner lose their job. “If you live in arural area and you lose your job, it's a lot harder to find anotherone than if you live in a more urban area,” Bredin said. “Sonecessity has become the mother of innovation for a lot of theserural female founders.” Discover the huffingtionpost.com's complete list of the top15 states for female entrepreneurs.