To be fair he repeatedly referred to it as "his grass".
He also referred to it as "his ranch". No, it's "his lease".
My wife's grandfather used to lease a couple hundred acres of land for farming from another landowner. He never called that piece "his farm". he always called it, "My lease".
I appreciate your post and the historical perspective it offered. I also appreciate your reference to case law. This issue is clearly complicated and I would like to understand it further.
It seems reasonable to contend that leased grazing land alone does not constitute a "ranch". Further, the notion of a "ranch" is generally thought of as including an amalgam of resources purposely gathered toward the raising of livestock. Grazing land (leased or otherwise) would be one of these resources. Other resources integral to a "ranch" could be: access to water sufficient to sustain humans and live stock, livestock, barns, accessory structures, a house(s), tools, implements, roads/trails, fences, gates, etc.
I'd argue, in the case of your grandfather's leased agricultural land, that although he didn't own it, in most contexts it would be reasonable and appropriate to included it in the spectrum of things that constituted his farm.
You posting from Wyoming and me from Massachusetts, our quibble over the notion of "Farm" and "Ranch" and the relationship of land to them has me thinking. Namely, that an examination of the colloquial vernacular used in ranching communities could shed light on what relationship "leases" have to the notion of ranch and what it's historical equivalents have been. The fate of the reality these vernaculars represent and has represented is what's being hashed out in courts. To do this fairly, the rancher's language and the relationships it describes should have been well translated into legal terms. I'm guessing this didn't happen. Then, over the last 80 years, the face to face, give and take, hand shake dealt, sidebar deals and the people who made them are all gone. These relationships and the agreements that came out of them tempered a law written by outsiders. The people in these communities have been left at the mercy of outsiders. Outsiders who who might not have the best interests of locals in mind.