Hello I see from your posting on Ancestry that you are related to Frank P Cowell thru his son Clarence's daughter Zetta who married a Mr. Green.
I also see that you do not have the date of the marriage of Clarence Cowell and Zerra May Eves. They married in Great Falls, Cascade County MT The date is 29 Sept 1899. If you want a copy of the license you can call the Clerk of Court in Great Falls to see what information you have to give to get one and the cost. 1 406 454 6780. If you belong to The Genealogy Benk under historical newspapers it has the small article when they applied for the marriage license and a small article when they married and who married them.
The 1900 Censes Clarence & Zetta lived in Dupuyer in Teton County MT 1910 Census Clarence and Zetta lived in Great Falls MT It said they have 2 children. LeRoy and Louis. You said( on Ancestry) that Frank LeRoy was born in Great Falls MT. If Louis was born in Great Falls and you want to get birth certificated on both you can call the Cascade County Clerk & Recorder's Office in Great Falls for information on what information you have to send and the cost. 1 406 454 6800.
Possibly if you post a message on Rootsweb in Casade County for an obit of Clarence Cowell for when he died in California PERHAPS the Great Falls Tribune may have picked it up because he lived in Grat Falls for a while.
The 1880 census Jefferson Scotland Co Missouro list
Frank P Maianda M Cowell Children Clarence P and Ada M. Missouri Marriage records list Franklin P Cowell and Marindee A Croley married 21 January 1875 Scotland Missouri. You pprobably could get their marriage license from Scotland County. You could check their website.
Missouri Birth Records list a son born to Mianda A & Frank P Cowell - Birth Date 21 March 1884. This child is not listed on the 1900 census.

The 1900 census lists:
Frank P Cowell and Miranda Cowell live in Dupuyer Teton County MT with children Jesse F, Alta A and Alma G. At that time Miranda said that she had had 6 children with 4 children living at that time.

The 1910 Census Long Beach CA lists F. P. Cpowell living with children Alta & Alma cowell. Also two lodgers, William Fergerson and Mable Griffith.

If you Google TETON COUNTY GENEALOGY MT- scroll down the TABLE OF CONTANTS you will find OBITURARY INDEX.
If you go thru them you will find an article on F P Cowell Teton County Long Beach CA 6 - 10 - 1907 and 6 - 6 1907 you can get copies of these from the Library in Choteau MT. There is other Cowell's listed in the list. Perhaps you will find the other 2 children of Frank P Cowell.
Possibly Alma married a Claude McIntyre on the 1920 and 1930 census living in Long Beach CA.
On the page of obits in Teton County Genealogy ssite they also list the obit of Alvin J Cowell. It is on the Teton County Rootsweb page that you also posted on. It also has an obit of his brother in law
I talked to the lady in charge of the Dupuyer cemetery. She told my that there are no HEAD STONES with the name of Cowell but that there are lots of UNMARKED graves.
Pondera County was established in 1919. Before that it was part of Teton County and Chouteau County. So if you want to get copies of information before Pondera was establiched you would have to go thru Teton County.
I am not related.
Linda