What is the best way to lock up a 4 wheeler left at the lease?

If somebody wants to steel it they can, I have seen people go to great lengths to steal stuff...such as driving a tractor through a barn wall to steel four wheelers.

I wouldnt leave it

Master makes a lock similar to a bicycle chain, but it's really thick cable and the lock is a thick piece of steel w/a keyhole in the middle instead of a padlock. They cost about $30. I have mine insured and lock it up with one of these, but I only leave it at the lease from about this time of year when I start filling my feeders until after deer season, not all year. And there is a lot of older retired people on our lease so there is almost always somebody there from the 1st part of August until after deer season, and it's only a few minutes from home so I go by every day. If it were further away I wouldn't leave it at all, but if you have to leave it ATV insurance is cheap compared to a new 4 wheeler....

true....also help if for some reason it goes down the road after coming off a trailer or the back end of a truck. I've never seen something that could be locked up that couldn't be stolen.

Get a metal cargo container - 4 hockey puck locks, square chain links with 7/16 lock on doors and solid steel cargo door locks. You can still get in but it would take a cutting torch and hopefully it will be too much trouble so they will go somewhere else.

Locks dont work anymore - the thieves now are using some kind of liquid that super freezes the lock and then hit it with a hammer - lock falls apart. At least that is what the sheriff said.

Liquid nitrogen will do that just fine, and almost every welding store sells it

Yep - that's it!

Best thing is to insure them, I have a policy with Liberty Mutual cost me $50/yr. You can't stop someone from stealing them and you will never see it again.