The Altar of Calgary is the second of three major altars. Like the other two, it is a combination of high relief sculpture in stucco and painting, but it consists of only one narrative panel depicting the crucifixion on Calvary. To the left of Christ are Mary, some of the disciples, and the repentant thief who was also crucified. Mary Magdalen kneels at the base of the cross.

The large relief panel is the work of Joseph Earley and Earley Studio. The painting surrounding the relief is likely by artists working with Earley Studio. Like the other relif panels, those that decorate the Altar of Calgary were originally delivered unpainted.