http://tcdailyplanet.tumblr.com/post/7081807388/ask-a-somali-why-are-there-so-many-somalis-in
...A lot of Somalis were brought here by Lutheran Social Service back in the 90s. And a lot of Somalis brought here to America due to the civil war of 1991 and moved to Minnesota from other states for jobs. Almost every Somali in Minnesota who came here between 1991 and 1998 worked at the chicken factories in Faribault and Marshall...
I believe there are also a bunch in Rochester: home of the Mayo Clinic.