Where art Thou Caribou?

According to the Committee on the Status of Endangered Wildlife in Canada, Boreal Caribou (formerly referred to as Woodland Caribou) occur in naturally low densities in mature boreal forest habitats. Based primarily on observation rather than any scientific studies it has been speculated that their range has receded northward to approximately the 50th parallel within Ontario and Quebec with some isolated southern populations such as the Slate Islands.

As an example Christopher Wilkinson published the following map in volume 28 of "Rangifer" (http://www.ub.uit.no/baser/septentrio/index.php/rangifer/article/view/147):

Note especially how the 2007 line compares with the range shown in the following map from "State of the Woodland Caribou Resource Report" published by Ontario Ministry of Natural Resources (MNR) in 2014 (https://www.ontario.ca/document/state-woodland-caribou-resource-report-part-1):

Amazing how reality (the second map) doesn't match very well with speculation (the first)!

Gord Miller, the former Environmental Commissioner of Ontario, stated in his 2010/2011 annual report that woodland caribou "to date only crude population estimates and delineation of herd ranges have been publicly available". This bears the question, why? And if all we have are "crude estimates" then how were they identified as an endangered species?

When the population is sparsely distributed how does one get a reasonably accurate census? Similarly back at the end of the 19th century, which is the time that most references to their former range refer to, how could they have been observed with confidence? The only access at that time in Northwestern Ontario was either by canoe routes or the recently established Canadian Pacific Railway (CPR). Even today occasional sightings are made far south of what is considered their current southern limit. Could those sighting from over a century ago have been of similar transients?

Even I have speculated that the Boreal Caribou may have moved north to where there is no interaction with humans. But in reflection that does not explain for example the herd in the Onaman Lake area that is south of the Canadian National Railway (CNR) which one would assume would be the southern boundary if that premise is true.

When it comes to caribou there is only one thing certain; we know very little about the species and only in the current century has much research been done. So why is a species that is found right across the width of Canada with its range pretty well defined by the northern half of the boreal forest a) considered "endangered" and b) the source of public policy when there is no evidence that human contact has had a negative impact on its range, both real or imagined?