Your ancestor, **Colonel Charles Jay Foster** was reported a retired jeweler at the time of his death. [See the earlier posted San Francisco funeral home reference]  

He married Mina Bauer on Saturday, March 23, 1889, in San Francisco, California. [*Sausalito News*, Friday, March 29, 1889, p. 3, c. 6.][1]

The engagement was announced in October, 1888; Charles was then the purchasing agent in Europe for Geo. W. Shreve & Co. See, [*Sausalito News*, Friday, October 12, 1888, p. 3, c. 2.][2] 

Geo. ... Shreve & Co., aka [Shreve & Co.][3], is reported by today's Wikipedia as the "oldest commercial establishment" in San Francisco.  

Charles J. Foster appears in various [San Francisco Directories][4] between 1889 (the time of his marriage) and 1880 (the date of the census entry about which you have inquired). (He probably appears in all the years, a few are listed below.) 

 - [Langley's San Francisco Directory 1888, p. 483][5]; Charles J. Foster, Geo. C. Shreve * Co., r. Union Club.  
 - [Langley's San Francisco Directory 1885, p. 481][6]; Charles J. Foster, with George C. Shreve & Co., r. Saucalito.
 - [Langley's San Francisco Directory 1880, p. 343][7]; Charles J. Foster, salesman George C. Shreve & Co., r. 1122 Pine. 

At San Francisco in the 1880 U.S. census is one one Chas. J. Foster, age 30 [indexed as 20], b. New York. [Link here to the FS index][8]; partial snippet below from Ancestry. This Chas. J. Foster is enumerated as a lodger in what seems a boarding house. (Page and image is not in good shape; other than to say it doesn't seem to be "Pine," I can't make out the street.) Occupation is "merchant"; entry remarks that he is "out of the ?city."  

![enter image description here][9]


SFgenealogy.com has other [San Francisco][10] information and directories online. There is probably a better way to navigate to it, but I used their page, ["Index of ... Directory."][11] to view images from Langley's 1879 San Francisco Directory. 

 - [image 71][12] is the directory title page. 
 - image 403 (actual page is 333) has entry, [Charles J. Foster][13], salesman, George C. Shreve & Co., r. 1122 Pine.

And ... they have the 1878 directory. 

 - [image 86][14] is the title page
 - image 414 (actual page is 330) has entry Charles J. Foster, salesman Anderson & Randolph, dwl NE cor Kearny and Post. 
 - (I couldn't quickly find an ad for Anderson & Randolph in the 1878 directory, but did find an ad for them in the 1879 publication. See the entry here: "[Randolph & Co.: **Jewelers**][15]," said "Successors to "**Anderson & Randolph**." 

I guess this is a long way of saying your Charles J. Foster was probably enumerated at San Francisco in 1880; he may be the man in the census entry provided. He likely resided there at least by 1878. 

**Your Charles J. Foster does not seem to be the man in 1880 stationed at Wyoming.** 

Would think it is possible for you to keep "inching" him back to see when he stops appearing in the San Francisco directories.  

-----
Wikipedia, "Colonel (United States)" suggests this military rank, "became rare" in the period after the Civil War; also "many brevet colonels were appointed again during the Spanish American War, prominent among them Theodore Roosevelt and David Grant Colson."

Although I suspect news about the time of his engagement and marriage would be a more timely reference, information follows that might help you locate an obituary. Have also included a news item that refers to him as "Colonel Charles Jay Foster."  

**On the trail of the obituary**:

With a 1929 death, there is at least a good chance the cemetery or mortuary has a copy of his obituary, or at least a newspaper reference. 

Do you have a copy of his death certificate? The (early) California Death Index reports his state [death record] file number is 28738. See entry, [Charles J. Foster (d. 9 May 1929)][16]; "California, Death Index, 1905-1939"; digital images, FamilySearch (accessed 2012), cites California State Registrar, California, Death Index; Office of the State Register; Sacramento, and the Butte County Courthouse, Oroville. 

[FindaGrave has memorial][17] for him at Cypress Lawn Memorial Park, Coloma, San Mateo County, California, 

Ancestry's collection of "San Francisco Area Funeral Home Records, 1895-1985," entry for "Charles Jay Foster" (dec'd 9 May 1929), reports the mortuary as N. Gray and Company; reports his occupation as "Retired Jeweler."  More about this mortuary and records on www.sfgenealogy.com; http://www.sfgenealogy.com/sf/sfranlib.htm#researchity. (Seemed to me perhaps better luck with the cemetery.) 

From the same funeral home, record for his widow, Mina (Bauer) Foster (d. 24 Oct 1943). Her parents John A. Bauer; Louise Hagen. (This seems the Bauer family with 9 yr old "Minna" at Austin, Texas in 1880.)    

**News item referring to family members; calls him Colonel Charles Jay Foster.**

Here is one of the news items; a dramatic story of the shooting death of a young woman. Charles Jay Foster is called "Colonel Foster." The woman killed is, it seems, his wife's niece. Oakland Tribune, January 14, 1913. 
![enter image description here][18]


  [1]: http://cdnc.ucr.edu/cdnc/cgi-bin/cdnc?a=d&d=SN18890329.2.31&cl=CL1.SN&srpos=0&e=------188-en--20-SN-1--txt-IN-Foster%20Bauer----
  [2]: http://cdnc.ucr.edu/cdnc/cgi-bin/cdnc?a=d&d=SN18881012.2.23&cl=CL1.SN&srpos=0&e=-------en--20--61--txt-IN-Foster%20Shreve----#
  [3]: http://en.wikipedia.org/wiki/Shreve_&_Co.
  [4]: http://archive.org/search.php?query=publisher:%22San%20Francisco%20:%20Francis,%20Valentine%20&%20Co.%22
  [5]: http://archive.org/stream/langleyssanfranc1888sanf#page/482/mode/2up
  [6]: http://archive.org/stream/langleyssanfranc1885sanf#page/480/mode/2up
  [7]: http://archive.org/stream/langleyssanfranc1880sanf#page/342/mode/2up
  [8]: https://familysearch.org/pal:/MM9.1.1/M6PH-2G7#
  [9]: https://i.sstatic.net/FgqG7.jpg
  [10]: http://www.sfgenealogy.com/sf/sfdata.htm
  [11]: http://www.sfgenealogy.com/sanfranciscodirectory/
  [12]: http://www.sfgenealogy.com/sanfranciscodirectory/1879/1879_71.pdf
  [13]: http://www.sfgenealogy.com/sanfranciscodirectory/1879/1879_403.pdf
  [14]: http://www.sfgenealogy.com/sanfranciscodirectory/1878/1878_86.pdf
  [15]: http://www.sfgenealogy.com/sanfranciscodirectory/1879/1879_5.pdf
  [16]: https://familysearch.org/pal:/MM9.3.1/TH-1961-26181-12441-58?cc=1932433&wc=14216746
  [17]: http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=63689763
  [18]: https://i.sstatic.net/ln568.jpg