The CLEO detector at the Cornell Electron Storage Ring (CESR) is completing
a major upgrade that significantly extends its physics reach in the study
of heavy quarks and leptons. The major elements of this detector upgrade ar
e the installation of a "fast" ring imaging Cherenkov detector, a new centr
al drift chamber and a new barrel-style silicon strip vertex detector. Trig
ger and data acquisition systems are also upgraded. We summarize the status
of these detector subsystems as well as the parallel CESR upgrade. (C) 200
0 Elsevier Science B.V. All rights reserved.