Stripe rust, caused by Puccinia striiformis, has become an important pathogen of hard winter wheat grown in the Southern Great Plains. Several hard winter wheat cultivars grown in the region have shown field resistance to stripe rust. The objectives of this study are to develop genetic populations between Great Plains adapted varieties with varying degrees of field resistance, and determine the number and type of resistance genes segregating in these populations. Crosses were conducted between six resistant cultivars and three susceptible genotypes. F₁ progeny were allowed to self-pollinate to develop F₂ populations. Two F₂ populations were used in genetic analysis. Two hundred F₂ individuals were inoculated with a 2003 stripe rust isolate. Inoculated seedlings were kept at 15 degrees Celsius until scored 14 days after inoculation. Chi-square analysis was done to determine goodness-of-fit of observed ratios to expected ratios in F₂ populations. A total of 14 resistant by susceptible F₂ populations and 16 resistant by resistant F₂ populations were developed, giving a total of 30 F₂ populations suitable for genetic analysis of stripe rust resistance. The first F₂ population scored was developed from a cross of Akron by Heyne where 21R:50I:32S ratio was observed. These results fit a 1:2:1 of one incompletely dominant resistance gene. The second population analyzed was from a cross of Lakin by Heyne where 49R:46I:18S seedlings. This observed segregation ratio fits a 7:6:3 ratio of one incompletely dominant gene and one recessive resistance gene. We conclude that the incompletely dominant gene comes from Heyne while the recessive gene apparently comes from Lakin. Adult plant screenings will be conducted to determine the number of adult plant genes present in these two populations.