Parking for this trail is at the easy to find Horsetail Falls Trailhead. The trailhead can be busy, but there are running water and flush toilets available here.
Look for the well-marked Pyramid Creek Loop Trail, and you'll head towards the creek. Families can enjoy a mini version of Horsetail Falls along the way, without having to worry about navigating terrain that is too strenuous. Just avoid the trail that branches off towards the Wilderness Boundary - that's a much more involved trail up to the actual Horsetail Falls.