On Nov. 5 a Federal Register notice was published describing the new Frontier definition methodology. You can find it at

Requests for Public Comments:
Methodology for Designation of Frontier and Remote Areas
Pages 66471-66476 [FR DOC# 2012-26938] PDF | Text | More

Comments are welcome. Please examine the materials on the Frontier definition posted at the University of North Dakota and the US Department of Agriculture as well.