The states with the highest concentration of rural students

According to Rural Policy Matters for November, 2009 the five states with the highest percentage of students enrolled in rural school districts are:

Maine                             54%

Vermont                        53%

South Dakota               51.3%

North Carolina            47.8%

Mississippi                    47.1%

Alabama is a close 6th with 41.4%

I would not have picked all of them.  It is interesting that North Carolina, Mississippi and Alabama are among the states with the highest number of students who do not complete high school.  Is there a correlation?