  We present the first weak gravitational lensing analysis of the completed
Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). We study the 64 square
degrees W1 field, the largest of the CFHTLS-Wide survey fields, and present the
largest contiguous weak lensing convergence "mass map" yet made. 2.66 million
galaxy shapes are measured, using a KSB pipeline verified against
high-resolution Hubble Space Telescope imaging that covers part of the CFHTLS.
Our i'-band measurements are also consistent with an analysis of independent
r'-band imaging. The reconstructed lensing convergence map contains 301 peaks
with signal-to-noise ratio {\nu}>3.5, consistent with predictions of a
{\Lambda}CDM model. Of these peaks, 126 lie within 3.0' of a BCG identified
from multicolor optical imaging in an independent, red sequence survey. We also
identify 7 counterparts for massive clusters previously seen in X-ray emission
within 6 square degrees XMM-LSS survey. With photometric redshift estimates for
the source galaxies, we use a tomographic lensing method to fit the redshift
and mass of each convergence peak. Matching these to the optical observations,
we confirm 85 groups/clusters with \chi^2 reduced < 3.0, at a mean redshift
<z_c> = 0.36 and velocity dispersion <\sigma_c> = 658.8 km/s. Future surveys,
such as DES, LSST, KDUST and EUCLID, will be able to apply these same
techniques to map clusters in much larger volumes and thus tightly constrain
cosmological models.
