E771 is a Fermilab fixed target open geometry high acceptance spectrometer experiment to study production of beauty states in 0.8 TeV proton‐nucleus interactions, and beauty decay particularly to final states containing a J/&PSgr; (detected via its decay to &mgr;+&mgr;−). The spectrometer consists of a silicon microstrip vertex detector (final configuration, 24 planes; x, y, u, v; of 25 and 50 micron pitch), upstream of which are beam‐defining planes of silicon microstrip detectors and target foils of various materials and thicknesses; the SVD is followed by tracking planes of drift‐ and proportional‐wire‐chambers, a momentum‐analysing bending magnet, further planes of DC’s, PWC’s and pad chambers, a &ggr;‐ and electron‐detecting lead glass wall, and finally several meters of iron interspersed with muon‐detecting resistive pad chambers and scintillators. Progress is reviewed in building, installing and tuning the equipment for the next Fermilab fixed target run beginning in mid‐1991, and expected to continue for 5 months. An extensive data run is anticipated for the 1993–4 fixed target period. In the 1991 run several dozen fully‐ reconstructed B to J/&PSgr; to &mgr;=&mgr;−events should be obtained per month of good running at an interaction rate of 2 MHz. For future runs the goal is to operate at 10 MHz and to reconstruct several thousand B decays per year to measure B decay branching ratios, study B0B¯0mixing, and search for CP violation effects.