An alternate route to the main Whatcom Trail was the Skagit Trail, which went up the river of that name to its headwaters, from which another "back valley" emerges on the Fraser near Hope, then the HBC fur trading post Fort Hope.
There are no known statistics for the number of goldseekers who travelled the Whatcom Trail during the gold rush, although certainly they may be counted in the thousands.
In part this measure was intended to prevent the entry of large parties of armed Americans, and also to strip them of any handguns and any goods for trading with the Indians (still a Hudson's Bay Company monopoly during the gold rush).
The route's ongoing use was demonstration of the early colony's essential inability to prevent unregulated intrusion by US citizens, as was also the case with the Okanagan Trail.
That allocation, however, was as much a response to local Stó:lō First Nations numbers as it was to potential American aggression.