Citizenship claim for son

[nwctzn]

Thanks again to all who helped in thread, filed about a month ago, received notice of action within a few days. Only thing confused on was how the form is forwarded after going to lockbox. Does it go to local office within residing state?

I think you're right. Looking at the processing times for local offices at the below link, it looks like they are processing the N600 applications:

https://egov.uscis.gov/cris/processTimesDisplayInit.do

It looks like it takes quite some time for the processing though.