Chullin 40 - Slaughter Done for the Sake of a Mountain
If one slaughters an animal for the sake of mountains, for the sake of seas, for the sake of rivers, or for the sake of deserts, his slaughter is invalid.
Had he slaughtered for the sake of the spirit of the mountain, it would clearly be an idolatrous sacrifice, and would be forbidden for all benefit. That would be true regardless of the importance of the idol, be it the greatest angel Michael or the smallest worm with spiritual qualities ascribed to it. So by right, slaughtering for the sake of a mountain should be allowed - but the Sages made it forbidden because it is too close to an idolatrous sacrifice. However, they did not go so far as to prohibit it for all benefit.
Rav Huna gave the following rule: if someone else's animal was lying in front of an idol, and one started to slaughter it - once he cut one pipe, or even less, makes a small cut - he made it prohibited for use. Even thought normally one cannot prohibit something that is not his, in a case like this, where he did an action, even a small action suffices.
Art: Gustave Dore - Gorge In The Mountains