Abstract: The formation of massive stars and star clusters is still poorly understood, despite its importance in cosmology, ecology of the ISM, and stellar demographics. We still debate such basic questions as the main formation mechanism and the timescales. However, a wealth of data from several new surveys promises to transform our understanding of this process. I will present background and new results from two large-scale surveys of molecular gas and star formation content of the Milky Way's 4th quadrant. CHaMP is a multi-wavelength, sensitive, unbiased, and uniform study of all massive star formation sites at sub-parsec resolution within a 20x6 degree window in Vela, Carina, &amp; Centaurus, including both the cold molecular gas and warmer areas heated by embedded young star clusters. The CHaMP clouds show a range of unexpected but key properties that shed new light on molecular cloud evolution and star cluster formation. ThrUMMS completely maps the remaining 60x1 portion of the 4th quadrant in 12CO, 13CO, C18O, and CN at arcminute- (ie, parsec-scale) resolution, and will be a key tool for obtaining distances to structures revealed by GLIMPSE, Hi-GAL, and many other surveys, as well as characterizing the physics of GMCs in more detail than possible previously. Both surveys feature freely downloadable image &amp; data files for custom analysis and other applications.