I think they ment the plant itself

Hasn't been built yet,or I can't find any evidence that it is.Just that the area you live in is perfect for a geothermal power plant,meaning what's going on underground,the thermal energy there is perfect for generating steam( in laymans terms of course,in reality it's way more scientific)
Actually have a newly formed theory,will explain only with your permission as it relates to you personally.

What is it?

I have followed this tread with great interest.There are certain things I believe in,the spirit world and afterlife to name two.At the beginning I did think what was happening in and around your home were strange and inexplicable but now I see everything in a different light.
The reasons for your tattoos,depicated a person who has suffered alot of trauma and loss in their life.Will list them for the benefit of other members,
Your sister's death.
A good friend in 9/11
Fellow comrades in war
Loss of part of your leg
Bud,whom you obviously adorned
More recently Ceasar,aged just 3
I can only presume that you also have seen things in your life that have caused you great pain.Imagine a person would have to be either very religious or unbelievably strong to get through all of this.Personally I think I would be in bits.
My point is that maybe you are suffering from some form of PTSD,perfectly understandable given the circumstances.
The animals behaviour I truly believe is caused by factors relating to the environment in this case,as they seem to have settled I'm guessing they are used to the noises they are hearing now.
The items moving in your home and the vision you had....I think the person responsible for that,albeit subconsciously is possibly......you.

Hi Isnt Medicine Lake the place of sacred burial grounds.Over here most mediums use a Red Indian to help them contact the other world,so you may be a bit mystical and a Red Indian can feel this and wants to connect Gemini54

My friend, who is an Indian medicine women and a psychic, says that there are multiple spirits on the property some Indian but she can't figure out who the rest are. Then there's the fact that are so hush hush about the property. I have no been diagnosed with PTSD, which is something I have had checked multiple times and may continue to do so just in case. I have friends who've come back from the war with mild cases of PTSD and they have no odd happenings in there homes, even my friends who have it severly don 't have odd things happening. My place is not my worry for a few days because I'm on my way back home and Loki is riding shotgun. My niece's eldest child is going to be stay over until I get back so if something happens while I'm gone then I know something is there. However I hope it doesn't because I want my family members to feel safe in my home.

If I was living in a house which I believed is haunted by Indian spirits who were showing themselves to me and moving things around my home,frightening myself and my animals....no offence I wouldn't be letting any family member stay there alone!! Why would you do that What if something does happen to him/ her?Why take the risk?
I don't understand.

I don't believe in any of this hocus pocus but would like to point out that 'Red Indian' has long been considered a derogatory term and is the name from which the other derogatory term 'Redskin' derived. And is described in dictionaries as usually offensive, disparaging and insulting.

Native American Indian is a more polite and proper way to refer to them now.

Hi I think it is the OP he/she is the one that is fey,so I dont think it will affect anyone else as they may not have second sight,and its as far as I understand poltergeist that show themselves once awakened by an event to everyone,but they are bad energy,and from what the OP is saying this seems just mischievous.Gemini54

Gemini,I'm not discounting your belief,everyone believes in different things.All I'm saying is OP is clearly believing something un-natural is going on in their home and choses to leave a family member there alone.Adding in the fact that the house seems to be a great secret with the locals for whatever reason,I don't understand why someone would do that is all.