On March 20, 1774, Juan Bautista De Anza, leading an exploratory expedition to find a good land route from southern Mexico to Alta California, reached the area today known as Riverside.
The routes taken by the two expeditions is believed to have followed a course from somewhere near Lake Perris, in current-day Moreno Valley, down the Box Springs grade near the 60/215 Highway interchange, and across Riverside in the direction of the Martha McLean - Anza Narrows park [REF].