Inheritance tax

I am kind of late but I just finished watching the whole YS series, and I’m still confused on how Beth and Kayce can’t afford to pay the tax after John died (correct me if I’m wrong here, based on my research is that inheritance tax doesn’t exist in montana, but in the series it does).

Is the money earned from auctioning the horses and equipments of the ranch not enough to pay the taxes? The ranch is approximately 885,000 acres right? and worth more than 8 billion so does that mean the tax would be worth 100+ millions? Sorry I don’t have that much knowledge about taxes.

Don’t they have any savings from the profit from the ranch and other investments?

Pardon my english, it’s not my first language