Patricia:
I would first contact an estate attorney, preferably in the California area where these minerals are located and sort out the history of what happened and what steps to take via California law in this situation. Your dad not having a will could require some legal expertise. If you and the others are deemed heirs to these mineral rights, they will have to be properly recorded at the County Clerk’s office in the county where these minerals are located. Before doing this, the other legal matters must be dealt with.