Hi,
I'd identify all information about Frank, Miranda and their children and then go back and look into collateral lines. Also if you can link up with any cousins, that's a great approach too.
Here is what I found.
I found the Drisdale Family Tree at Ancestry, which contains information about Franklin P. Cowell.
Franklin P. Cowell, b. 17 April 1853 Monroe, Ohio.
Franklin married 1875, Scotland Co., MO but wife is unknown.
He lived in Dupuyer, Teton Co., MT. He died 3 June 1907 Long Beach, Los Angeles Co., CA. Source=Drisdale Family Tree.
A Franklin P. Cowell of Scotland Co., MO married Marendee S. Croley of Scotland Co. on 21 Jan. 1875, Scotland Co at John Croley's home. Source=Missouri Marriage Records 1805-2002.
In 1880 Frank and Miranda were living in Jefferson, Scotland Co., MO.
Frank P. Cowell b. IA, 27, farmer.
Maranda M., wife, b. MO, 26.
Clarence P., b. MO, 3.
Ada M., b. MO, 1.
I think Ada may have died young because I didn't find her after this Census.
A male Cowell
Born=21 March 1884, Jefferson Township, Scotland, MO
Mother=Miranda A. Cowell, 30 yrs old
Father=Frank P. Cowell, 31, farmer.
Source=Missouri Birth Records 1851-1910.
Frank, Miranda and children in 1900 were living in Dupuyer, Teton Co., Montana. (at one time Teton was in Pondera Co.)
Frank P. Cowell, b. IA April 1853, marr 25 yrs, farmer.
Miranda A., wife, b. MO June 1859, gave birth to six children but only four alive in 1900.
Jesse F., son, b. MO Jan 1886.
Alta A., dau, b. MO April 1888.
Alma G., dau, b. MT May 1896.
In 1910 Miranda and children were living in Long Beach Ward 3, Los Angeles Co., CA.
Mrs. F. P. Cowell, b. MO, 56, widow, had given birth to six children but only four alive in 1910, no occupation.
Alta A., b. MO, 21, single, saleslady dry goods store.
Alma G., b. MT, 13.
Wm N. Fergerson, lodger.
Mabel Griffith, lodger.
In 1920 Miranda was living in Long Beach next door to Alma & Claude McIntyre. Some time after the 1910 but before 1920 Census Miranda married a mr. Graves but he died before the 1920 Census.
Miranda W. Graves, b. MO, 65, widow, no occupation.
In 1930 Miranda was living in Long Beach.
Maranda C. Graves, b. MO, 76, widow, no occ.
A Miranda Ann Graves
born=14 June 1853, Missouri
Died=6 Aug 1949, Los Angeles Co.
Father's Surname=Croley.
Source=California Death Index 1940-97.
You can find an obituary volunteer at Obituary Lookup Volunteer-California, freepages.genealogy.rootsweb.ancestry.com/~obitl/ .
Ask them to look up Frank's too.
OR
Contact the Long Beach Public Library,
www.lbpl.org/ .
In 1900 Clarence and family were living in Dupuyer, Teton Co., MT.
Clarence Cowell b. MO Sept. 1876, marr <1 yr, farmer.
Zetta, wife, b. WA jan 1876.
Edith Rand, borader.
John Powers, boarder.
John Ryan, boarder.
In 1910 Clarence and family were living in Great Falls, Cascade Co., MT.
Clarence Cowell, b.MO, 34, marr 11 yrs, motorman street ____.
Zetta, b. WA, 33, had given birth to three children but only two alive in 1910.
Le Roy, b. MT, 5.
Louis, b. MT, 1 7/12ths.
A Clarence Pierce Cowell was living in Cascade Co., MT on Sept. 11, 1918.
Born=29 Sept. 1876.
Occupation=motorman, Montana Power ____, Great Falls
Nearest Relative=Zetta Mary Powell? can't read rest.
Source=World War I Draft Registration Cards 1917-18.
In 1920 Clarence is living in Great Falls.
Clarence P. Correll, roomer, b. MO, 43, conductor street railway.
In 1920 Zetta is living in Los Angeles Assembly District 75, Los Angeles Co., CA.
Zetta M. Cowell, marr, b. WA, 42, no occupation.
Minnie V. Herman, sister, b. IN, 40, widow, no occupation.
In 1910 Jesse Cowell and family were living in Great Falls Ward 4, Cascade, MT.
Jesse Cowell, b. MO, 26, marr 3 yrs, crusher man smelter.
Margaret, wife, b. MO, 26.
Everett, son, b. CA, 9/12ths.
A Jesse Frank Cowell on Sept. 4, 1918 was living at 751 Ottawa St., Los Angeles, Los Angeles Co., CA.
Born=21 Jan 1886.
Occupation=____ shipyard, unemployed.
Nearest Relative=Mrs. Cowell Graves, 441 Linden Ave., Long Beach.
Source=World War I Draft Registration Cards 1917-18.
In 1920 Jesse was living in Los Angeles Assembly Dist. 75, Los Angeles Co.
Jesse F. Cowell, lodger, b. MO, 33, divorced, mechanic auto shop.
In 1942 a Jesse Franklin Cowell
b.=21 Jan 1886, Memphis Co., MO
Residence=Neal Rd., Paradise, Butte Co., CA
Occupation=Self-employed.
Nearest Relative=Mrs. Lula P. Cowell.
Source=U.S. World War II Draft Registration Cards 1942.
A Jesse Franklin Cowell
b.=21 Jan 1886, MO
Died=19 April 1953, Los Angeles Co.
Mother's Maiden Name=Crowley [what appears on index]
Father's Surname=Cowell.
Source=California Death Index 1940-97.
First I'd contact the Long Beach Library for a copy of his obituary. If they don't have it, you'll need a copy of his death certificate.
Contact the Los Angeles County Registrar-Recorder, Norwalk, CA. Do a Google search for the contact info.
The McIntyre Family Tree, trees.ancestry.com/tree/17398341/person/505393394 contains info about Miranda Ann Croley.
An alma Gertrude Cowell b. 1 May 1896 Dupuyer, ,Montana died 1 Nov 1995, Medford, Jackson Co., OR. She also married Claude Edwin McIntyre.
Claude Edwin McIntyre b. 19 April 1894 Ada Co., Idaho died 14 April 1961 medford, jackson Co., OR. Source=McIntyre Family Tree.
In 1920 Alma and Claude were living in Long Beach, Los Angeles, CA.
Claude Mcintyre, b. MT?, 25, driver sightseeing car.
Alma G., b. MT, 23.
Sharmon, dau, b. CA, 2 11/12ths.
In 1930 Claude, Alma and family were living in Long Beach.
Claude E. Mcintyre, b. ID, 35, marr @ 21, subdivider real estate.
Alma G., b. MT, 33, marr @ 19.
Charmon, dau, b. CA, 13.
Robert, b. CA, 8.
Anna Warsaw, maid.
A Claude F. Mcintyre died 14 April 1961, Jackson Co., OR per death cert #4138. Spouse=Alma.
Source=Oregon Death Index 1903-98.
A Robert E. McIntyre
Born=2 Jan 1922
Last Residence=Medford, jackson co., OR
Died=20 Aug. 1995.
His soc. sec. # was assigned in CA before 1951.
Source=Social Security Death Index.
To find their obituaries, contact the the Jackson County Genealogy Library, rvgslibrary.org/index.html . Successful Searching & Happy Holidays!