We present an experimental study of intravalley and intervalley transport in an InAs/AlSb/InAs/AlSb/InAs double barrier resonant tunneling diode at liquid helium temperatures. This work reports the first observation of intervalley tunneling through an InAs Γ‐point quasibound state confined by AlSbX‐point barriers. The incident energy of tunneling electrons was tuned by a transverse magnetic field (0<B<17 T). Self‐consistent calculations of the current‐voltage relation and a model that includes a transverse wave vector contribution to the magnetic field behavior of the resonances are used to describe the experimental results. From this, we determine that the device current is composed of Γ‐point InAs electrons tunneling through X‐point AlSb barriers (with large longitudinal effective mass) as well as Γ‐point AlSb barriers.