The Opal Cone lava flow is interesting because it is easy to miss when you are standing beside it but it's blatantly obvious when seen in satellite photos.
“Opal Cone is a cinder cone located on the southeast flank of Mount Garibaldi in the Coast Mountains of British Columbia, Canada. It is the source of a 15 km long broad dacite lava flow with prominent wrinkled ridges. The lava flow is unusually long for a silicic lava flow.”
We drove down the Mamquam River Main to within one or two km of the Mamquam L Line (old logging road.) The road was snow covered with ruts. We were in an Outback with aluminum skid plates and decided to stop once we were continuously scraping the bottom. It shouldn't be a problem for anyone with a 4WD truck and decent tires to get to the start of the L Line at this point in time.
With our limited time budget, we stayed to the L Line and got to within a few km of the end. I'd be interested in going back one spring when there is a deep snow pack and going to the end of the L line and then dropping onto the flow itself. Based on Google Earth, It looks like once the flow turns the bend, the trees thin out and travel may be easier with deep snow cover. I'm not sure how much closer you could get to the Cone in those conditions before there is too much avy danger but it looks like you could get pretty high. The spots we saw from the ridge varied from dense trees to more open rocky areas with light snow cover. Neither option looked very fun so I'm glad the road was easy to travel on.
A primary goal of the trip was to get a good look at the flow and in particular, the amount of vegetation/rocks.
Travel was fast. We had to wrestle with some slide alder but nothing excessive. We topped out just below 800 m. With snowshoes we were only sinking 1-3 inches. We started and finished the hike in boots.
Being on top of the south-east ridge, we got a few good views. When time ran out, we took a small detour to a view point for lunch and then made our way back to the car. My tea-lights in a tin can are working great for keeping fingers warm over lunch. If you are into geology, it's a neat area to check out.
Stats: 5 hours, 14 km (total), 350m