I have copies of 3 books of newspaper extracts that Mary McRoberts did.
One is : "Boulder County, Colorado / Marriages, Anniversaries, Divorces, Births and Birthdays / 1859-1900 / Newspaper Abstracts / Mary McRoberts / Boulder, Co/July 1991"
Another is : "Boulder County, Colorado / Deaths and the Insane / 1859-1900 / Newspaper Abstracts / Mary McRoberts / Boulder, Co / July 1991"
And : "Genealogical Abstracts from the Boulder Daily Camera / 1891-1900 / Boulder, Colorado / Mary McRoberts
First they only go up to 1900, so they wouldn't have caught Zel's birth. And I'm getting, what I find to be, scattered hits. One hints his father may be Thomas J. Thompson ; another implies T.J. Thompson is County Commisioner. But for a person of that role there is surprisingly little else written. They may have been in another county most of this period ; I know my own ancestors there bounced all over the place.
Also Thompson is a fairly common name and had a lot of entries. I kept my search focused on T.J and Hattie only (I know you didn't list a Hattie but see below).
And finally, check out the dates ; you could make an arguement that the Lamsons were Zel's great-grandparents.
Here's what I found on the Lamson / T. Thompson families listed in chronological order :
1.Births "Lampson [sic ?], Mr. & Mrs. John - dau b.31 Dec 1871 Upper St. Vrain. CN 5 Jan 1872:3)" [CN=Boulder County News]
2.Obit - " Lamson, Flora E. d 25 Apr 1873 Upper St. Vrain. Age 1 year 3 months. (CN 2 May 1873:3 ; could this be dau of Mr. & Mrs. John Lamson, b 31 Dec 1871 Upper St. Vrain?)" [CN=Boulder County News ; this is Mrs. McRoberts' note and she may have written it because of the spelling ibn the birth annoucement above.]
3.Obit "Lamson, John d 13 Feb 1876 at Corning Tunnel, Gold Hill of consumption. (CN 18 Feb 1876:2)" [CN=Boulder County News]
4.Marriage "Thompson, Thomas J. of Gold Hill, m 12 April 1881 Hattie E. Lamson at home of bride's mother in Boulder by Rev. C.M. Campbell. (NAC 15 Apr 1881:2)" [NAC=Boulder News and Courier]
5.Marriage "Lamson, William S. m 6 June 1888 Mary Ada Smith, both of Jamestown, at home of Joseph R. Bailey in Boulder by Rev. J.A. Ferguson, (BN 12 June 1888:4 ; HW 13 June 1888:8)" [BN=Boulder News , HW=Boulder County Weekly Herald]
6.Obit "Lyons, Miss Mary d 9 Oct 1892 of consumption at home of county commissioner T.J. Thompson in Boulder. Has been in Colorado 6 years. Mrs Lampson took remains to Yellowstone, WI. (BN 13 Oct 1892:4)" [BN=Boulder News]
What I didn't find (and makes me wonder) - No births for a T or Thomas Thompson ; these books would cover 19 years of their married life. No obit for Mary Lamson. And I noted that there is a Yellowstone in Lafayette County Wisconsin and one in Monroe County Indiana. Name "Lyons" ring a bell ? And could they have been WI instead of IN ? Or is this a typo (in the Lyons obit)?