The Martha McLean Anza Narrows Park is located near where Anza crossed the Santa Ana River its narrowest point in surrounding area in present-day Riverside, California. The colonizing expedition found this narrow river crossing a quite difficult ford due to deep, fast moving water. They had to improvise a bridge using parts remaining from the earlier Anza exploratory expedition. A cow and a horse were lost in this river which Anza described as "...very crystalline and beautiful." A few cottonwoods were found along the river.