Choice of germplasm determines breeding success and failure. As a consequence, successful breeding procedures will not extract outstanding products if the genes desired are not present in the selected germplasm. Public maize (Zea mays L.) breeding programs are usually limited in their choice of germplasm. Some of the reasons associated with this limitation are 1) lack of access to elite private genetic materials for breeding purposes 2) limited resources for extensive testing 3) limited use of successful heterotic combinations 4) limited search for useful genetic diversity 5) occasional long-term germplasm improvement efforts. Useful genetic diversity in reserve can only be present through continuous genetic improvement of elite genetically broad-based and genetically narrow-based populations. The number of successful heterotic combinations currently available is limited. Heterotic patterns of population hybrids with high mid-parent heterosis values have not been exploited. The purpose of the presentation is to share the strategies used by North Dakota State University to choose maize germplasm for the northern Corn Belt. Marginal regions of corn production are an opportunity to exploit diverse genetic resources through the identification of alternative heterotic patterns, adaptation of elite germplasm, and exploitation of genetic diversity as a consequence of long-term genetic improvement in the public sector.