Abstract: Compositions and methods are provided for stacking multiple independent transgenic loci into the genome of a plant. Compositions include plants, seeds or plant cells comprising at least one transgenic target site and at least one genomic locus of interest integrated at different genomic sites within a genomic window. Plant breeding techniques can be employed such that the transgenic target site and the genomic locus of interest can be bred together. In this way, multiple independent transgene integrations can be generated within a genomic window to create a complex trait locus. The complex trait locus is designed such that the transgenic target sites and/or genomic loci of interest can segregate independently of each other, thus providing the benefit of altering a complex trait locus by breeding-in and breeding-away specific elements. Various methods can also be employed to modify the target sites such that they contain a variety of polynucleotides of interest.