Legal Question in Civil Litigation in Nevada

Start by putting your demand in writing and sending a certified letter to the next-door neighbor. Talking is one thing, but you need a provable paper trail if this matter is not quickly resolved. This is the best way to demonstrate (to a judge or whomever) that you made a good faith effort to solve the dispute amicably.

You are legally entitled to remove branches that extend over your property line - and certainly any that place your structure at risk - so long as you engage in "self-help" that does not permanently damage the tree. In other words, you cannot just hack away at a branch without ensuring the tree is not hurt by it, but your neighbor most certainly is responsible for his own trees and their maintenance.

Your next step might be to call an arborist, get an estimate for the trimming (of what is over your line), and hit the neighbor up for that amount (another certified letter). If he won't get it done, himself, and you want to be a little more intimidating, you can tell him that you MUST get the work done and may be forced to sue him in small claims court and get a judgment lien against his property for reimbursement.

Another angle is to notify your homeowner's insurance company that your house faces this risk, that you have no direct control over it, and you just want them to be aware that if you suffer some casualty loss, they are going to have to chase down the neighbor for reimbursement of any claim they pay out to you for damages. Your agent might actually get on the phone or send a very official-looking letter to the neighbor and act as your advocate to protect their own investment.

Good luck!