Locations of 6.7 GHz Class II methanol masers detected with the VLA (blue circles) toward the dense molecular ridge extending from DR 21 M in the south to DR 21 (OH) (and beyond), overlaid on a 70 μm dust continuum image obtained with Herschel (red scale; Hennemann et al. 2012). Gray contours represent the GLOSTAR combined B+D-array continuum emission. The magenta contours show the velocity-integrated absorption of the 6.7 GHz methanol line. The nth contour is at , where: S_max = 1.2 Jy beam⁻¹, n = 1, 3, 5..., and p is equal to 0.4% for the continuum; and n = 0, 1, 2..., S_max = −3.2 Jy beam⁻¹ km s⁻¹, and p = 16% for the methanol absorption. The white stars and green Xs mark, respectively, the positions of Class I methanol masers observed in the 95 GHz 8₁−7₀ A⁺ line (Plambeck & Menten 1990) and the 18 cm OH masers associated with DR21(OH) and W75S-FIR 1 (Norris et al. 1982; Argon et al. 2000). The orange stars represent 44 GHz Class I methanol masers (Kurtz et al. 2004).