Amazing powder zones on Grouse Mountain. Thrasher Creek and The Ridge are great places to get some vert. Backside Cliff is the best drop on the mountain. There are plenty of sick features hidden within the trees which I have not specifically marked off too. Setting the traverse trail across at the top of The Ridge is usually the toughest bit when the pow is fresh, there is usually some sidestepping involved. You want to maintain a really high traverse as this way it is easier to access the goods on far skier's left. Make sure not to drop off the skeir's left edge into Thrasher Creek unless you have already explored Thraser and know where you are going to get funnelled into, it gets really nasty back there.
Note that this is a backcountry ski area and that proper precautions should be taken. Be prepared to ski with avalanche peeps, probe, and shovel. Know how to use them and know the snowpack conditions. Get to know the area beforehand. Explore the areas on Google Maps/Earth and understand how the terrain rolls and plot you exit route. Before venturing into these zones in the winter, we would hike around in the summer and get to know the landmarkers and exit route. Also note that Grouse has a very strange out of bounds policy. We actually got banned for life from skiing back in Thrasher Creek, the routes are there for informational purposes and to make us lament of the bizarre management. Riding the Outer Limits ride is usually ok, I've bumped into ski patrollers out there and given high fives on the pow, and other times they have scolded me.... so ya, they're weird.