I handle many interstate child custody cases. You may be able to file a petition for custody and support in CA, since CA apparently is now apparently the children's home state under the UCCJEA (Uniform Child Custody and Jurisdiction Enforcement Act), which has been enacted in all states. I am admitted to practice in Washington and New York States, but not CA. I cannot represent or advise you on your specific case. However, I have provided representation or consultation on interstate custody cases many times, and attorneys in other states sometimes call me to consult on UCCJEA questions.
It is possible that you could succeed in vacating or modifying the existing NV court order in a NV proceeding. This can be difficult to do, but the circumstances of your case may provide the court with good reasons to do so, especially if you experienced or had a reasonable fear of domestic violence.
What the CA or NV court will do in your case ultimately depends on the individual facts. A good attorney may be able to uncover facts that are unknown, or may seem insignificant to you. You should consult a competent CA or NV attorney as soon as possible.
We do a very large amount of interstate (and international) family law work; many such cases touch Nevada, where we are located.
Preliminarily, it is never a good idea to ignore court proceedings. And there are mechanisms that could, and should have been, put into place to protect youi no matter what threats were made. Do not be intimidated into inaction.
What I can't tell from your story is whether dad did, and/or still does, live in Nevada. If so, and if the original orders were from Nevada, then I respectfully suggest the other attorney who wrote in is wrong, because this State maintains "Exclusive Modification Jurisdiction." For an explanation, see the article titled "The Basics of Family Law Jurisdiction," on the Published Works page of our firm web site, at http://www.willicklawgroup.com/published_works. For a pretty comprehensive view of how custody litigation in Nevada works, see the materials posted at http://www.willicklawgroup.com/child_custody_visitation.
If, as I think you are saying, you and the children are not in Nevada and they have never been in his custody, then there is grounds for vacating the order -- even five years later. But this is going to take a good deal of work. Please look over the child support materials posted at http://www.willicklawgroup.com/child_support. And I am not too worried about people lying about income and assets. It happens all the time, and competent counsel have ways of trying to discover the truth. It is difficult to "hide" a "big house and business."
We have, in other cases, moved to set aside orders entered mistakenly, or fraudulently, with some success, but it is never simple, and the passage of time makes it all the more difficult. For background, see the article entitled "Partition Actions and Fraud on the Court," posted at http://www.willicklawgroup.com/published_works.
Time is not your friend, and sooner is better than later. We can do what needs to be done by long distance, but you should act ASAP. If you decide you would like to discuss this with one of the attorneys of this firm, please take a look at our consultation policies, procedures, and costs, at http://www.willicklawgroup.com/consultation_policies. If your case is in Reno, while we do some work in Washoe County, you may wish to deal with counsel there. In either event, you should probably seek consultation with an appropriate family law specialist. I would suggest starting your search with the American Academy of Matrimonial Lawyers, the Nevada chapter of which can be viewed at http://www.aaml.org/go/fellows/fellows-by-state/?showResults=true&state=NV. Feel free to share this e-mail with whomever you do contact.
Whatever you decide to do, good luck.