For South Shore access: Getting here is a little tricky, but not too bad. Pass the Carr Powerhouse and follow the road until it ends and turns sharp left onto a dirt road. Follow this road for 2.7 miles, and you'll eventually come across a gate on both the left and right side of the road. Park and go up the one on the right (the sign says Boulder Creek Falls).
Mill Creek Access: Take Carr Powerhouse Road to Mill Creek Road, located on the right 0.5 mile from the highway. Mill Creek Road is a dirt road that is closed after the first winter storms and reopened in late spring. At the road crossing just past the big tank, stay to the right. You'll follow Mill Creek Road steadily uphill for 1.3 miles until you reach the trailhead. At the end of the road, you'll see a wide spot for parking and two paths.
The trail is pretty straightforward and well-marked. Keep in mind that there are four stream crossings, some larger than others. Rocks can be slippery, and the crossings are tougher after heavy rainfall or in spring with heavier flow from snow melt. There are large leaf maple trees along the way which makes for gorgeous scenery in the fall!
Approaching the falls, the trail drops down into a cool watershed. The creek leading from the falls is visible, crossing the road. The sign for the short side trail to the falls will be on your left. Hop on the Boulder Creek Falls Spur
and follow the steps up the hill to a rocky vantage point where the main falls can be seen.
Pine, fir, oak, maple, dogwood, and ferns.