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Mary Olson — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Fergus-County, Montana
Our Model Tree links this Mary Olson across the 1930 and 1940 US Censuses in Fergus-County, Montana (XGBoost, ~Confirmed) — first a daughter (b.~1927), then head of a 12-person household.
Age 13
b. ~1927
Female
Daughter
Born: Montana
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Fergus-County, Montana |
| Surname | Olson |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Montana |
| 1935 Residence (City) | School Dist. 82 Grass Range |
| 1935 Residence (County) | Fergus |
| Additional Details | |
| Industry | 0 |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Montana |
| Birth Country | United States |
| Birthplace (normalized) | montana |
| Township / Ward | School Dist 82 Grass Range |
| Est. Birth Year | ~1927 |
Household Members
Census records only state relationship to the household head.
Pairwise kinship is derived (~90–95% accurate), not recorded.
Step/blended families and boarders can break it.
12 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Ole Olson | Head | — | 57 | ~1883 |
| Esther Olson | Daughter | — | 7 | ~1933 |
| Donald Olson | Son | — | 4 | ~1936 |
| Willis Olson | Son | — | 12 | ~1928 |
| Hazel Olson | Daughter | — | 12 | ~1928 |
| Mary Olson | Daughter | — | 13 | ~1927 |
| Hendry Olson | Son | — | 10 | ~1930 |
| Roy Olson | Son | — | 15 | ~1925 |
| Inga Olson | Spouse | — | 47 | ~1893 |
| John Olson | Son | — | 27 | ~1913 |
| Ramona Olson | Other | — | 17 | ~1923 |
| Gladys Olson | Daughter | — | 18 | ~1922 |
Census Appearances
1930
Fergus, Montana
Daughter, age 3
Fergus, Montana · implied b. ~1927 — 14 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Olson |
| Given Name | Mary L |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Montana |
| Father's Birthplace | Norway |
| Mother's Birthplace | Norway |
| Birth State | Montana |
| Birth Country | United States |
| Birthplace (normalized) | montana |
1940
Fergus-County, Montana
Daughter, age 13
Fergus-County, Montana · implied b. ~1927 — 12 household members
| Surname | Olson |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Montana |
| 1935 Residence (City) | School Dist. 82 Grass Range |
| 1935 Residence (County) | Fergus |
| Industry | 0 |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Montana |
| Birth Country | United States |
| Birthplace (normalized) | montana |
Model Tree
An inferred pedigree reconstructed from census links — up to 4 generations within the 1900–1950 window. Closer generations are built from household co-residence; deeper ones are bridged by following a relative to their own childhood census. Confidence compounds and weakens with each generation.
Our Model Tree links Mary Olson across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Olson
Daughter · 1940 · age 13 · b. ~1927 · Montana
★ You are viewing this record
Sibling
Esther Olson
Sibling · 1940 · age 7
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Hazel Olson
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Olson
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Gladys Olson
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Willis Olson
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Roy Olson
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Hendry Olson
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Donald Olson
Sibling · 1940 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Fergus-County, Montana
Open full size
1940 US Federal Census — Fergus-County, Montana
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02218-00605)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Elliot G. Lee | 53 | Head | Farmer | Iowa |
| 2 | Valentine Lee | 60 | Wife | — | Norway |
| 3 | Ole Olson | 57 | Head | Farmer | Norway |
| 4 | Inga G. Olson | 47 | Wife | — | Norway |
| 5 | John Olson | 27 | Son | Partner | Montana |
| 6 | Ramona Olson | 17 | Dtr. in law | — | Montana |
| 7 | Gladys Olson | 18 | Daughter | — | Montana |
| 8 | Roy Olson | 15 | Son | — | Montana |
| 9 | Mary Olson THIS PERSON | 13 | Daughter | — | Montana |
| 10 | Willis Olson | 12 | Son | — | Montana |
| 11 | Hazel Olson | 12 | Daughter | — | Montana |
| 12 | Hendry Olson | 10 | Son | — | Montana |
| 13 | Esther Olson | 7 | Daughter | — | Montana |
| 14 | Donald Olson | 4 | Son | — | Montana |
| 15 | Bard Trigen | 35 | Head | Stockman | Montana |
| 16 | Ann Trigen | 30 | Wife | — | Montana |
| 17 | Bard C. Trigen | 12 | Son | — | Montana |
| 18 | Eleanor Aasen | 20 | Housekeeper | Housework | North Dakota |
| 19 | Magnus Aasen | 25 | Hired hand | Hired Hand | North Dakota |
| 20 | Carl Johnson | 58 | Hired hand | Hired Hand | Sweden |
| 21 | Arthur Poetter | 37 | Hired hand | Hand | Montana |
| 22 | Charles Mccartney | 26 | Hired hand | Hired Hand | Idaho |
| 23 | Oswald Olson | 25 | Hired hand | Hired Hand | Montana |
| 24 | Nels Jepperson | 64 | Hand | Farm Hand | Denmark |
| 25 | Louis J. Cheyrette | 57 | Hand | Herder | Montana |
| 26 | J. M. Mcglothlin | 68 | Hand | Herder | Texas |
| 27 | Daniel Baker | 39 | Hand | Herder | North Dakota |
| 28 | Carl Olson | 68 | Hand | Herder | Norway |
| 29 | James Dudley | 52 | Head | Farmer | Idaho |
| 30 | May H. Dudley | 50 | Wife | — | Iowa |
| 31 | Thomas Dudley | 13 | Son | — | Montana |
| 32 | Sarah Dudley | 84 | Mother | — | Arkansas |
| 33 | Elmer E. Loebs | 55 | Head | Farmer | South Dakota |
| 34 | Susie Loebs | 54 | Wife | — | Minnesota |
| 35 | Ruth Loebs | 17 | Daughter | — | Montana |
| 36 | Wayne Myers | 30 | Head | Farmer | North Dakota |
| 37 | Mildred Myers | 30 | Wife | Farmer | South Dakota |
| 38 | Leona Myers | 7 | Daughter | — | Montana |
| 39 | Merlin Myers | 5 | Son | — | Montana |
| 40 | Victor Stromnes | 49 | Head | Farmer | Minnesota |
Related Census Records
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1940 United States Federal Census (NARA). Our Model Tree links this person across census decades using XGBoost-based record linkage, with per-link confidence scores. Household corroboration strengthens the signal when co-residents appear on the same census pages in multiple years.
Source: National Archives and Records Administration (NARA)