Selection is continuing to improve biological efficiency of rangeland beef production systems. Selection criterion are increased values of: 1) a yearling weight minus birth weight multiplied by 3.2 index; and 2) a calf weight at weaning divided by cow weight ratio Environmental trend is being monitored using a randomly mated and randomly selected control. Selection line response patterns are being measured relative to rate and magnitude of animal growth, food intake, reproduction success, and carcass attributes. Breeding schemes to develop backcross resource families needed to identify segregating molecular genetic markers in Line 1 Hereford and Composite Gene Combination (CGC) composite populations is continuing. Focus is on identifying molecular markers with phenotypic components of biological and economic importance. In addition, research is continuing to conserve unique Line 1 Hereford germplasm while continuing the historical selection for increased postweaning growth. Also, technology continues to be developed that statistically integrates biological and economic information so as to allow consistent selection of beef cattle whose offspring are more profitable or efficient and produce products that meet consumer expectations.