Globally, many migratory mammals are facing threats. In northern Canada, large annual ranges expose migratory caribou to an array of human activities, including industrial exploration and development. Recognition that responses to human activities can accumulate for caribou is long-standing, but is heightened by recent declines in caribou abundance. For example, since the mid-1990s, the Bathurst herd has declined by approximately 90%, leading to severe harvest restrictions. More mines are being proposed and developed across the herd's annual range, raising questions about cumulative effects. Despite progress on assessment techniques, aboriginal groups are expressing strong concerns and frustration about gaps in responsibilities for who should monitor, mitigate, and manage cumulative effects. The core of the concern is sustainability and the related trade-offs between industrial developments relative to continued access to healthy caribou for harvesting. We offer insights into how these concerns can be addressed by building on existing concepts (adaptive management) and approaches (herd management).