I recently purchased in Jacksonville, OR, the subject photos of a father and three of his children.
One photo depicts 47 people on the steps and porch of a wooden building. Four heads are marked with an "X", including three Armstrongs. The photo is identified on the back of the mount:
"Portland Woolen Mills Zellwood Erected Jan 1902 Consumed by fire Feb 18, 1904 Dick X ) Armstrong his Dad X) Stella X Armstrong Mrs Bergman-on left above (Cy Bergman's mother)"
The other photo, taken by The Rembrandt Studio, Portland, OR, depicts two boys, and is identified on the back of the mount:
"Dick - 12 years 1902) Armstrong brothers Arthur 8 years.) Arthur Died Mar. 1906 at 12"
This familyappears in a Public Member Tree posted on ancestry.com. It is listed in the 1900 Census data for Canemah Precinct, Clackamas Co., OR. In about 1887, Frank L. Armstrong, born Aug 1861 in NY, married Loretta Freeman, born Apr 1872 in IL. Frank worked as a weaver in woolen mills. The couple had five children: Stella Armstrong, born Apr 1888 in NE; Richard Earl Armstrong, born 19 Feb 1890 in Cozad, Dawson Co., NE, died 31 May 1987 in Portland, Multnomah Co., OR; Carrie Armstrong, born Jan 1892 in NE; Arthur Armstrong, born Jun 1894 in OR, died 26 Mar 1906 in Multnomah Co., OR; and Ethel Armstrong, born Jun 1896 in OR.