Abstract. The term strong approximation is used to describe phenomena where an arithmetic group as well as all of its Zariski dense subgroups have a large image in the congruence quotients. We exhibit analogues of such phenomena in a probabilistic, rather than arithmetic, setting.Let T be the binary rooted tree, Aut(T ) its automorphism group. To a given m-tuple a = {a 1 , a 2 , . . . , a m } ∈ Aut(T ) m we associate a tower of 2m-regular Schreier graphs . . . → X n → X n−1 → . . . → X 0 .