structure north and east of the W3(OH) cluster [these groups have been previously identified; e.g. @Feigelson:2008vn; @Navarete:2011ys]. In Figure \[fig:W3OH\] we show a close-up image of this region, where we now combine H and K images with the Spitzer IRAC 3.6 $\mu$m image to enhance illuminated nebulosity features and highlight the most reddened sources. We have labeled the W3(OH) cluster with the letter ‘A’. The two other most conspicuous groups in the ’chain’, both associated with B-type stars [@Navarete:2011ys] have been labeled with letters ‘B’ and ‘C’. The former group is not as prominent as an over-density but as it can be seen in the mosaic, it is associated with thick nebulosity, so it is possibly more deeply embedded. There is one more bright source sitting at the center of a cavity in between groups B and C, which we suspect could be an additional sub-group.

![image](./f2im.eps){width="6.0in"}

### Catalog preparation \[s:observations:ss:nir:sss:catalogs\]

The OMEGA 2000 photometry was calibrated relative to the Two-Micron All Sky Survey (2MASS), using catalogs retrieved from the All Sky Release Point Source databases. Final photometry catalogs were prepared with aid of `TOPCAT-STIL` [@Taylor:2005uq]. We combined individual photometry catalogs from each frame and filter and merged catalogs from 