Most work on high-mass star formation has focused on observations of young massive stars in protoclusters. Very little is known about the preceding stage. Here, we present a new high-resolution study of pre-protocluster regions in tracers exclusively probing the coldest and dense gas (NH_2_ D). The two target regions G29.96-0.02 and G35.20-1.74 (W48) are drawn from the SCAMPS project, which searches for pre-protoclusters near known ultracompact HII regions. We used our data to constrain the chemical, thermal, kinematic, and physical conditions (i.e., densities) in G29.96e and G35.20w. NH_3_, NH_2_ D, HCO^+^, and continuum emission were mapped using the VLA, PdBI, and BIMA.

Cone search capability for table J/A+A/530/A118/table1 (List of stars)