The highest point of the area around Mount Vancouver is actually about 2 km north of the border. It's height is 4812m and is at 60.35867, -139.69783. We can refer to this peak by its Bivouac areaname of DG59. The peak on the border is at 60.33483, -139.69284 and can be referred to as Peak DG39.
Below is a table which summarizes:
DG59 Mount Vancouver 4812m
DG39 Good Neighbour 4785m //on border
Unfortunately both the US and Canadian Maps label the one on the border as "Mount Vancouver", and have no name on the high point. It is our belief that the true location of Mount Vancouver is the high point. The other point on the border is referred to as "Good Neighbour".
Both USGS and Canadian maps refer to the south summit as Mount Vancouver. This is incorrect, the south summit is Good Neighbor, Vancouver being the north summit. There is at least one intermediate high point on the ridge between which is unnamed.