Pass Lions Bay. You'll cross a small bridge 'M Creek Bridge' just a little bit after on your left is a pull out, park there. There are 24 spots. You won't be able to turn in and will have to drive further up the highway to safely turn around. Your hike starts at the north end of the parking lot across the street. Careful as you cross as the traffic on The Sea to Sky Hwy can be busy & fast. You’ll see a 'Rockfall Hazard' sign. The trail is just before that with a little yellow sign. There are no tunnels but several rocky outcrop with views. The great thing about this hike is you can choose any of the 8 viewpoints to stop at. Of course the top is the best.
Tunnel Bluffs is a very well marked trail. I only wish it had the Km's & elevation marked on each of the trail markers, so you knew how much further you had to go. You will start climbing right away. As you climb keep a lookout for several rocky bluff view points, some nicer than others. They all have little 'view' signs.
You’ll cross a few logs cut out like stairs and will keep going steeply up for an hour. Along the way there’s a couple rope assists to help you up or down. When you come to the second rope assist it levels off. It's a beautiful walk on an old logging road that's really a path and old growth forest. Some of the trees are what you would see before logging began. There are some beautiful Arbutus trees and some that were so wide I couldn't wrap my arms around them.
It is here where you will cross a couple of creeks, one named 'Yahoo Creek.' It's very peaceful. Finally you will come to a sign indicating you've done 5 Km's with 1 to go to the final viewpoint. It's still level for a bit then some loose rocks for a short time. There are two viewpoints at the top. One is amazing while the other is covered in the trees.
When your done head back the way you came... It's a steep, slippery trek down...Be careful! I wore my MICROspikes and it helped. I would suggest poles for your descent. If you want you can carry on another 6 Km's to Hat Mountain, where there is a nice little cabin you can but expect much of what you have already done. Happy & safe trails.