There are now several high-resolution structures of HIV-1 envelope glycoprotein (Env) trimer, the key target for broadly neutralizing antibodies. Nearly all structures however are of the soluble, stabilized, prefusion conformation of Env, and there is little variability between the structures. It is well appreciated that Env is a flexible, meta-stable protein capable of undergoing large receptor-induced conformational changes to perform its role in host cell recognition and entry. Here we use cryo-electron microscopy (cryoEM) to study several different conformations of Env, including the CD4 bound state, at high-resolution to describe the molecular details that stabilize these intermediate states and enable Env to function. Additionally, we compare the structures of the soluble stabilized trimers to those of the wild-type transmembrane containing Env to derive insights for HIV vaccine development.