  We report the phase diagram of $\lambda$-(BETS)$_2$GaCl$_4$ from rf
penetration depth measurements with a tunnel diode oscillator in a pulsed
magnetic field. We examined four samples with 1100 field sweeps in a range of
angles with the magnetic field parallel and perpendicular to the conducting
planes. In the parallel direction, $H_{c2}$ appears to include a tricritical
point at 1.6 K and 10 T with a phase line that increases to 11 T as the
temperature is decreased to} 500 mK. The second phase line forms a clearly
defined high field low temperature region satisfying several of the conditions
of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. We show remarkably good
fits of $H_{c2}$ to WHH in the reentrant $\alpha>1$, $\lambda_{so}=0$ regime.
We also note a sharp angle dependence of the phase diagram about the field
parallel orientation that characterizes Pauli paramagnetic limiting and further
supports the possibility of FFLO behavior. Unrelated to the FFLO study, at
fields and temperatures below $H_{c2}$ and $T_c$, we find rich structure in the
penetration depth data that we attribute to impurities at the surface altering
the superconducting properties while maintaining the same crystallographic axes
as $H_{c2}$.
