Horsetail Falls is on Pyramid Creek. Pyramid Creek flows into the South Fork of the American River. My first outing to Horsetail Falls did not meet with great success. I underestimated the difficulty of the hike. To an experienced hiker it would not be that hard. But I over packed and started late. I'm also not used to the altitude. I made it about ¾ of the way to the base of the falls and ended up turning around and heading home. Now that I know what it's like I expect to make it to the falls next time.