for snowmobiles purchased from a dealer, you can use as proof of ownership the Manufacturer's Certificate of Origin or the Manufacturer's Statement of Origin. There are some more options.
What in case the owner dies. How does the transfer go?
In case the owner is deceased, the Estates , Powers & Trust Law of New York State takes care of providing for the transfer but only through the property distribution of an estate set up by a Surrogate Court. The surviving Spouse, minor shield or next kin can't assume the ownership automatically.