Help save our 3 Generation family home

We are 3rd generation family living in a historic home that was built in 1942 outside of Billings, Mt. Our lively hood is threatened because of action taken or not taken.  A portion of our house is now precariously hanging over the edge of the riverbank and if we cannot take immediate action we will lose our home that we have worked so hard to keep in the family.  We have tried working with the county to resolve the issue, but they will not spend the money to resolve issues on private property because of State and Federal permits required we where unable to take action by our family.  Our neighbor up stream has acquired a second permit that we are able to use also.  Our portion of the riverbank is $70,000 but the remaining $200,000 is required from River Grove Estates above us.   We have flood insurance but it does not cover erosion. Our home has been zoned outside the 100 year high water mark and it has been affected by drastic changes that have been made by diversion dams built by State and unauthorized alterations to a natural flow of the river.  We are asking for help to keep our home from becoming an unnecessary loss and to help save countless others that will be threatened downstream if we are unable to take immediate action to restore the riverbank. Thank you for your help.