  A deep mid- and far-infrared survey in the Extended Groth Strip (EGS) area
gives 3.6 to 8\micron flux densities or upper limits for 253 Lyman Break
Galaxies (LBGs). The LBGs are a diverse population but with properties
correlated with luminosity. The LBGs show a factor of 30 range in indicated
stellar mass and a factor of 10 in apparent dust content relative to stellar
mass. About 5% of LBGs are luminous at all wavelengths with powerful emission
at rest 6\micron. In the rest 0.9 to 2\micron spectral range these galaxies
have stellar spectral slopes with no sign of an AGN power law component,
suggesting that their emission is mainly powered by intensive star formation.
Galaxies in this luminous population share the infrared properties of cold
SCUBA sources: both are massive and dusty starburst galaxies at $2<z<3$; their
stellar mass is larger than $10^{11} M_{\odot}$. We suggest that these galaxies
are the progenitors of present-day giant elliptical galaxies, with a
substantial fraction of their stars already formed at $z \approx 3$.
