According to a report from the Urban Institute, little attention has been given to the geographic distribution of student loans and how it relates to cost of attending college in a state. The states where the largest shares of college students have student debt are in the Midwest and the Northeast. The Western region of the country has the lowest share of college students with student loans. The share of the college-going population with student loans in a state is positively associated with the average cost of attending a public four-year institution.
The report can be obtained at https://www.urban.org/sites/default/files/publication/97751/where_is_student_debt_highest_0.pdf.