What does thd lease say?
Was it drawn up on the back of a napkin or is it well written? It should be binding on heirs and assigns.

although you can likely force them to honor the lease, if they want you gone they can be on the property constantly, driving away the deer while they keep your money.

I'd suggest you not just focus on what they can legally do, but also if they are likely to make what you paid for worthless. Getting the money back might be the least bad option.

Do they live locally? They may just want to sell it, maybe they just want to lease it for more than you paid? I believe here you can have the lease recorded with the county and it would go on the deed for the duration of the lease.

I'm not sure ide walk away from the lease...maybe it's a good time to offer to buy the property if you can afford it.

he passed away last week and his kids and grandkids called and told us to stay out

First of all, emotions are running in overdrive right now considering he just passed away. I would cautiously hit the pause button and give reasonable amount of time.

signed contract with him and his present wife I forgot the legal term, but the contract defaults to solely the wife having survivorship. The kids or grandkids do not have a legal say in anything with direct communication to you. Obviously they will plead their case to the wife and family usually trumps outsiders.

I have AG leases on my property, so not exactly the same but over-all same concept. Neighbor leases X amount of land, he carries the cost for prep and maintenance. Because of fertilizing and erosion control plans, we have agreed to a 1 year notice for non-renewal. Many people don't look at that, but it protects him and me in the event either of us don't want to proceed with a lease extension

I would take a friendly approach to the wife. Sending card/flowers to the funeral and making a very NON-defensive but sincere condolences to the wife/family. Then follow up later with wanting to touch base with her on the lease and terms, maybe asking about her views for the long term. Legally, you own the right and will win the battle, but will lose the war. Do you have the two years or only 1 remaining?? Possibly discuss a buy out on the lease if they are head strong on kicking you out that would include time and expenses of your investment?

If the end result is you getting kick out before the lease is up, you have the right to sue her for breach of contract and recover ALL your costs and possibly the difference of the increased cost to secure a different lease. Additionally, you have legal rights as part of that lease. If the kids/grandkids prohibit you from utilizing the land as part of the original intent of the lease, they are liable for harassment and it falls under a breech of contract.

It can get ugly fast, but if your getting kicked out there is no need to be nice. Sue them for every penny you can recover. Its not like they'll invite you back at a later time