  We establish exponential decay, as the angle of twisting goes to $ 0$, of
eigenstates in a model of twisted bilayer graphene (TBG), near the hexagon
connecting stacking points. That is done by adapting microlocal methods
Kawai-Kashiwara and Sj\"ostrand used to establish analytic hypoellipticity by
Tr\'epreau and Himonas. That replaces ellipticity, absent here, which is the
usual mechanism behind classically forbidden regions. We also discuss numerical
evidence of exponential decay in other regions (the center of the hexagon) and
analytic complications involved in establishing that decay.
