  We present a multi-wavelength study of a 3.6 $\mu$m-selected galaxy sample in
the Extended Groth strip. The sample is complete for galaxies with stellar mass
$>10^{9.5}$ \Msun and redshift $0.4<z<1.2$. In this redshift range, the IRAC
3.6 $\mu$m band measures the rest-frame near-infrared band, permitting nearly
unbiased selection with respect to both quiescent and star-forming galaxies.
The numerous spectroscopic redshifts available in the EGS are used to train an
Artificial Neural Network to estimate photometric redshifts. The distribution
of photometric redshift errors is Gaussian with standard deviation
${\sim}0.025(1+z)$, and the fraction of redshift failures (${>}3\sigma$ errors)
is about 3.5%. A new method of validation based on pair statistics confirms the
estimate of standard deviation even for galaxies lacking spectroscopic
redshifts. Basic galaxy properties measured include rest-frame $U-B$ colors,
$B$- and $K$-band absolute magnitudes, and stellar masses. We divide the sample
into quiescent and star-forming galaxies according to their rest-frame $U-B$
colors and 24 to 3.6 \micron\ flux density ratios and derive rest $K$-band
luminosity functions and stellar mass functions for quiescent, star forming,
and all galaxies. The results show that massive, quiescent galaxies were in
place by $z\approx1$, but lower mass galaxies generally ceased their star
formation at later epochs.
