The Behavioral Risk Factor Surveillance System (BRFSS) is a State telephone based survey of the civilian non-institutionalized adult (18 years and over) population residing in the United States. Consequently, the BRFSS final weights that are currently available in the data files are designed to produce unbiased estimates of socio-demographic and health characteristics for adults at the State level (Gonzalez, et al, 2005). In addition to State level BRFSS estimates, there is interest in the health status of adults residing in the 25 U.S. counties contiguous to the United StatesMexico Border region (Arizona, California, New Mexico, and Texas.) The purpose of this paper is to investigate alternative ways of arriving at poststratification factors (ratio adjustments) by collapsing the weighting matrix by age-sex-ethnicity/race for producing final weights/estimates for this border region. An optimal approach which minimizes local (cell) squared bias was applied to BRFSS data (25 contiguous counties). Then, a conditional mean square analysis was used to observe the effect of cell collapsing (in tandem with the optimal bias approach) on the absolute bias and variance estimators for several BRFSS socio-demographic and health characteristics.