Earthquakes can cause extensive physical damage to the components of power transmission systems. This physical damage can trigger massive outages affecting millions of residents. Further, the physical damage can trigger cascading outages which are a series of dependent outages which can further impair the power transmission system and extend outages to a substantially larger geographic area.There is extensive literature focusing on the restoration process for electric power transmission systems. However, several gaps exist in that literature that are addressed in this dissertation. The first gap is the impact of cascading outages. The second gap is the characteristics of the outages at high geographic resolution. The third gap is the impact of recent increases in the deployment of rooftop solar plus storage on the resilience of the power transmission system. The first study focuses on integrating cascades into an existing capacity expansion investment model for mitigating the impacts of earthquake damage to the power transmission system. A case study is developed using the Eastern Interconnect transmission grid where the primary seismic hazard stems from the New Madrid Seismic Zone. The results show that cascades have little effect on the capacity expansion investment, but they do have a significant impact on the early stages of the recovery process. The second study develops a load shed distribution method to create a probabilistic representation for load shed during the recovery process in Los Angeles at the census tract level. This analysis reveals the vulnerable areas in the city, and that the damage of substations is the key driver of load shed. The third study explores the impact of increased deployment of residential rooftop solar plus storage. The reduction in load shed during earthquake events that stem from the adoption of solar plus storage is analyzed at the census tract level. This analysis demonstrates that this deployment does improve the resilience of the transmission system. However, the distribution of this improvement is correlated with household income and whether the home is owner occupied or is rental property.