Alternatively, there is the claim that Father Lucian Pulvermacher, OFM Cap was elected Pope Pius XIII in 1998 in Montana. He was consecrated Bishop by "Gordon Cardinal Bateman" from Australia. The website tells us the news:
The ceremony was held in a rented hotel ballroom in Kalispell, Montana, USA. There were 28 members of the faithful in attendance, some travelling thousands of miles to witness this awe-inspiring event.Sadly, some of his supporters have since deserted him owing to allegations that he practised divining using a pendulum.
Then again, there is David Bawden who was elected Pope Michael I in Kansas in 1990. This was valid because Pope John XXIII, Paul VI and John Paul were all heretics. They could not therefore appoint Cardinals so by 1990, there was only one true cardinal left. He was a modernist so he couldn't elect a Pope. Therefore, faithful Catholics were bound, under pain of mortal sin, for the good of the Church, to elect a Pope themselves. Now, Catholics who subjected themselves to any of these false popes can't vote. Traditionalists are not true Catholics and all their ordinations are invalid so they can't vote. Therefore, the faithful remnant legitimately elected him the Pope (he claims about 30 followers worldwide.) QED.
In addition, there are the following (with dates and places of election):
Peter II, Maurice Archieri, 1995, Paris, France
Peter II, Julius Tischler, Germany
Peter Romanus II William Kamm (Little Pebble), Australia
Gregory XVII Gaston Tremblay, St. Jovite, Canada, 1968
Gregory XVII Clement Diminquez y Gomez, Palmar de Troya, Spain, 1978
Hadrian VII, Francis Konrad Schuckardt, 1984
Valerian I, Fr. Valerio Vestini, Avezzano, Italy, 1990
Linus II, Victor Von Pentz, England, 1994
[That's enough antipopes. Ed.]
My researches on this fascinating subject have led me to understand the crucial difference between sedevacantists (who say there is no Pope) and conclavists (who elect their own). There is an article here on Sedevacantism which explains it all.
With a little fit of scrupulosity, I realised that I should refer you (should you need it) to an article called Do-It-Yourself Popes: the Wacky World of Sedevacantists (from This Rock) which gives a sensible debunking of the whole thing.