  We present a 3x3 degrees, 105-pointing, high-resolution neutral hydrogen (HI)
mosaic of the M81 galaxy triplet (including the galaxies M81, M82 and NGC 3077,
as well as dwarf galaxy NGC 2976) obtained with the Very Large Array (VLA) C
and D arrays. This uniformly covers the entire area and velocity range of the
triplet with a resolution of ~20'' or ~420 pc. The data reveal many small-scale
anomalous velocity features highlighting the complexity of the interacting M81
triplet. We compare our data with Green Bank Telescope (GBT) observations of
the same area. This provides evidence for a substantial reservoir of low-column
density gas in the northern part of the triplet, probably associated with M82.
Such a reservoir is not found in the southern part. We report a number of
kpc-sized low-mass HI clouds with HI masses of a few times 10^6 Msun. Their
dynamical masses are much larger than their baryonic masses, which could
indicate the presence of dark matter if the clouds are rotationally supported.
However, due to their spatial and kinematical association with HI tidal
features, it is more likely that the velocity widths indicate tidal effects or
streaming motions. We do not find any clouds not associated with tidal features
down to an HI mass limit of a few times 10^4 Msun. We compare the HI column
densities with resolved stellar density maps and find a star formation
threshold around 3-6 10^20 cm-2$. We find that extreme velocity dispersions can
be explained by a superposition of multiple components along the line of sight
near M81 as well as winds or outflows around M82. The velocity dispersions
found are high enough that these processes could explain the linewidths of
Damped-Lyman-alpha absorbers observed at high redshift.
