  The Cygnus region hosts the most conspicuous star-forming region close to the
Sun, embedded in a giant complex of molecular clouds in the Local Arm. We
present an analysis of the Fermi-LAT observations of Cygnus intended to probe
the cosmic-ray and interstellar-matter content of the region. From gamma-ray
data we estimate a total of (8 +5 -1) x 10^6 solar masses of interstellar gas
in the complex at a distance of 1.4 kpc. The gamma-ray emission from the atomic
gas supports the average HI spin temperature derived from radio
absorption/emission pairs to estimate its column densities. The
X(CO)=N(H2)/W(CO) ratio derived in the massive Cygnus complex is consistent
with other LAT estimates for clouds in the Local and Perseus arms. The mass of
dark gas, escaping HI and CO observations but traced by dust and gamma rays,
amounts to ~10% of the total. We find an average gamma-ray emissivity per
interstellar H atom in the 0.1--100 GeV energy band in good agreement with
measurements in other segments of the Local Arm. We infer that the cosmic-ray
population averaged over a few hundred parsecs is fairly uniform in density and
spectrum along the Local Arm. Despite the presence of potential accelerators
and much larger interstellar densities in Cygnus compared to the solar
neighborhood, their cosmic-ray populations are similar on such a scale.
