Data from 770 records of Hereford, 25% Simmental - 75% Hereford, 50% Simmental - 50% Hereford and 75% Simmental - 25% Hereford cows were used to evaluate whether breed group means for maternal traits agreed with expectations based on the dominance model. Cows were managed consistent with practices for western range environments. Cow breed group was significant for 17 of the 18 traits studied. The measure of goodness of fit of the breed group means to the dominance model was the R2 value associated with the linear regression of breed group means on proportion of Simmental for the first three breed groups. Most of the traits agreed with the dominance model expectation (83% of the R2 values were greater than .75).