C-band image of the W51A region with diffuse H ii regions labeled. The labels are above the circles except where arrows are used. The regions labeled W51 Main 65 kms RRL shell and W51 Main 40 kms RRL shell are part of W51 IRS1 (e.g., Zhang & Ho 1997); we have given them independent labels here because we are now able to kinematically distinguish them in RRL emission and because they are evidently part of (or interacting with) a large shell centered near W51 Main.