Was curious as to how things turned out and it appears things went well for at least a year or so.Found following in 1870 Federal census for San Francisco which seems to be a fit:
Henry M. Condon, age 30, native of MA Mary Condon, age 23, native of MO Wm. Condon, age 1, native of CA
However, I have not been able to find the family in any other census.
I note from a Grass Valley attractions write-up that 78 acresofundevelopedland was bequeathed in 1957 by a Lulu Condon to the City of Grass Valleyforrecreational purposes. It indicates this land was once a portion ofthe Chollar Ranch and was acquired by a Henry Condon(Lulu’sfather)in1867 and theBoundary Minewasdeveloped here.I assume this is the Condon Park in Grass Valley which which shows up on Topozone.
As noted in original post, I'm not related, but am sort of curious if this is the same family and if so, why they're not showing up in other census', and if there's a "local historian" that has any info along these lines?