  We search for young stellar objects (YSOs) in the L1641N cluster and
characterize the star formation activity through determination of the age
distribution, mass function, spatial distribution, and the star formation
history.
  We detect a total of 216 (Spitzer or $I$ band) sources in L1641N, 89 of which
are YSO candidates. Most of the spectra are of M-type with H$\alpha$ strongly
in emission, and many have Li 6707 in absorption. The four brightest $I$ band
sources (F and G stars) are suggested as foreground stars, and the L1641N IRAS
source is shown to be the combined flux of at least four sources. We find that
the interstellar extinction is well-fit in the optical and near-IR by a power
law with an exponent of 1.58, although in the mid-IR the Spitzer observations
show a higher extinction than expected from theory. The median age of the YSO
sample is $\sim$1 Myr and the resulting MF has a flat distribution for low
masses down to the completeness limit. There is evidence of a constant star
formation rate of one star in 3.7 $\times$ 10$^4$ yr during the past few Myr.
We find 11 sources older than 10 Myr and a spatial separation between younger
and older YSOs, suggesting that many of the older stars formed in L1641N could
have left the cluster, giving the appearance of an increased star formation
rate with time.
