A history of Mount Rubidoux, a mountain just west of the city of Riverside, California, that has been designated a city park and landmark. The mountain was once a popular Southern California tourist destination and is still the site of the oldest outdoor non-denominational Easter Sunrise service in the United States. Many historic markers and memorials have been placed on the mountain, the most prominent being the cross at the summit dedicated to Father Junípero Serra. In particular, this work focuses on the efforts of Frank Augustus Miller (1858-1935), the owner and chief developer of the Mission Inn in Riverside. In 1906 Miller, along with Henry E. Huntington and Charles M. Loring, formed the Huntington Park Association and purchased the property with the intent to build a road to the summit and develop the mountain as a park to benefit the city of Riverside. Originally the park was named Huntington Park, but the name was changed to the Frank A. Miller Mount Rubidoux Memorial Park after the heirs of Frank Miller donated the property to the city in 1955.