<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> -ray spectroscopy of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi>La</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>140

$^{140}\mathrm{La}$ is an important isotope in nuclear forensics. It is typically paired with $^{140}\mathrm{Ba}$ as a chronometer for dating nuclear events. In this work, we report the results of two measurements performed to fully characterize the decay scheme of $^{140}\mathrm{La}$. The experiments were performed using the Gammasphere array at Argonne National Laboratory and the CLARION2 array at Florida State University. Sources of $^{140}\mathrm{La}$ were produced through neutron irradiation of natural lanthanum (99.9% $^{139}\mathrm{La}$) in the University of Massachusetts Lowell research reactor. We identify a total of 40 transitions, three of which were not previously reported. An angular correlation analysis was conducted confirming current literature $J$ assignments and mixing ratios. By considering all data available in the literature, we provide new recommended values for the intensities of the strongest transitions commonly used in applications.