Why did settlers and native Americans clash in the backcountry?

Settlers did things like occupy and degrade popular hunting grounds or water sources. Like if a settler built a house and barn and fences somewhere, it might ruin the place as a hunting ground because the animals might shy away from it. A fence in a pasture might block and annoy a Native American who was traveling across that area. In some cases, settlers unknowingly violated taboos. Like maybe they cut down trees from a holy grove to use for timber or firewood.