This is a first for this blog: this stamp is not within the city limits of Lansing. It is just barely inside the convoluted borders of Lansing Charter Township. More specifically, it is on the north side of East Michigan Avenue between the two US-127 overpasses, just east of Feldman Chevrolet. S & N Contractors stamps are present at intervals all the way under both overpasses. There must have been a big overpass construction project in 2000. I have a very vague memory of the freeway being closed for a stretch when I was new in town, so that lines up.
I believe that S & N Contractors is most likely the one that was once located on Lansing Road, with a Charlotte address but located closer to Dimondale. OpenCorporates gives their dissolution date as 2005. I notice that the State of Michigan Department of Transportation’s materials source guide dated March 2014 lists them as an approved supplier. I don’t know whether or not that means they were still around in some form by then. In any case, they no longer seem to be in business.