I checked the 1930 census for Colorado and did not see them listed.
The closest I could come was this and the film was really really bad on ancestry.com
1930 Queens, Queens, NY
Sweeney, John, head, m, w, 55, m 25 yrs, NY, Free State, Free State, can't read occupation.
Sweeney, Sarah, wife, f, w, 55, m 25 yrs, NY, NY, NY.
Sweeney, ?Harold?, son, m, w, 23, NY, ?furniture patinter?
Sweeney, Can't read, son, m, w, 21, NY, Can't read
Sweeney, Can't read, son, m, w, 17, NY, Can't read
Sweeney, ?Roe Mary?, daughter, f, w, 15, NY
Sweeney, Anna, daughter, f, w, 12, NY
Keller, Mary E, sister, 44, single, NY, NY, NY
I checked the SSDI and found a John Sweeney in it.
b. 15 July 1876
d. Oct 1955
No "last residence" listed.
SSN was issued in CO before 1951
b. 27 March 1876
d. May 1968
last residence listed as Loveland, Larimer, CO
SSN was issued in CO 1965
I checked several cemeteries that I have acess to the index and did not see any Sweeney's listed.They are
Loveland Cemetery, Loveland
Lakeside Cemetery, Loveland
Resthaven Cemetery, Loveland
Grandview Cemetery, Fort Collins
Roselawn Cemetery, Fort Collins
If they died here they may of been buried back in NY.I would contact the Larimer County Genealogical Society at P.O. Box 270737, Fort Collins, CO 80527-0737 and ask if they can do an obituary lookup for you.
I hope this helps.