Vital records are records that chronicle birth, death, marriage, and divorce. Many of these can be difficult to track down, especially if the researcher is trying to find freely available information online.
Marriage and divorce records can often be difficult to obtain. The best bet is to look at the county clerk's website for the county in which the couple were married or divorced to get more information.
In Oklahoma Marriage licenses are recorded with the county clerk. Some are available through the OSCN dockets.
Divorce information may also be obtained by searching local court dockets.
The Social Security Death Index is available for free online. This resource is available through many different websites and can help the researcher determine if an individual is deceased. Some examples are at FindMyPast, and FamilySearch.org, Free registration may be required for these websites.
Another option is to use SortedByName.com, which actually lists the Social Security numbers of many deceased people.