The garden is designed to draw spiritual pilgrims, something that concerns the original inhabitants, who fear escalating property prices and an erosion of their way of life.
So far, sensitivity to the tribes' concerns seems to have been shown and the article ends on an upbeat note. Still, I can't help but wonder about the "rightness" of what should be a lovely and serene installation. Does the wealth that allowed the land to be bought and the garden to be built somehow taint the concept? Or, is it just part of the natural unfolding of things with the passage of time?
Considering the number of religions that have steamrollered over the previous religions over the centuries, I think that any "peaceful" arrival of another religion is fine. While I am not the sort of person who approves of religions in any case, I would say that creating a new place of worship is far superior to stripping out the previous religion and placings one's icons in the existing site -- such as happened in places like Constantinople or Jerusalem.
What I find interesting is that those Montana tribes -- native people of the new world, which has a long history of steamrollering & displacing the original inhabitants -- have made another displaced people and religion so welcome, and have done it by finding similarities between the two groups.