At the right time of year, when the runoff from snowmelt is near its peak, this run can be absolutely remarkable. The destination is the waterfall, but the scenery along the creek on the way up is great the whole way.
The upper part of this trail is quite slippery on wet granite, and the lower section can be quite crowded with families. This might not be the most runnable of trails.
Parking for this trail is located at the easy-to-find Pyramid Creek Trailhead. The trailhead can be busy, but there are running water and flush toilets here. A nice way to tackle this route is to start with the well-marked Pyramid Creek Loop Trail
, and you'll head towards the creek. Families can stick to this loop and enjoy a mini version of Horsetail Falls along the way, without having to worry about anything too strenuous if you have youngsters who can make the full run.
For the full journey up to the falls, take the Pyramid Creek Trail
that branches off towards the Wilderness Boundary. On this section, you'll scramble a bit over granite, and you might feel like you've lost your way at times, but essentially, you'll be headed straight up towards the falls, with the creek on your right. When you get to the falls, it's possible to continue beyond the end of the marked trail, but don't attempt this unless you're a skilled backcountry runner. It's slippery and potentially quite dangerous towards the top of the falls.
Play around for a bit, then continue back the way you came. You can take either route back down when you get to the junction with the Pyramid Creek Loop Trail
, as both branches will return you to the trailhead.