Although the Kalispel remained largely isolated from white settlements until the 1860s, they felt the impact of white incursion — by way of disease — as early as 1760. While it is impossible to know with certainty the impact of disease on Indians of the interior Northwest, ethnographer James Teit estimated that between one-third and one-half of all Plateau people died as a result of disease in the early 1780s.
The effects of early epidemics would subside but disease would continue to torment the Kalispel into the mid-twentieth century. A shrinking land base and resulting poverty directly affected the health of the Kalispel who disproportionately suffered from tuberculosis, influenza, and diabetes.
