The delayed entry of solar protons (Ep>0.2 MeV) into the Earth's magnetotail has been studied by simultaneous observation with three Earth-orbiting apacecraft of a sequence of specially favorable events during 1968. Principal findings are that (1) such protons have immediate access to the magnetosheath; (2) delay times increase discontinuously from essentially zero in the magnetosheath to tens of minutes as an observing point moves inward across the magnetopause; (3) well-defined delay times in the range 30--160 min occur for points interior to the magnetotail; (4) the inferred entry points lie at downstream distances of 80--500 RE; and (5) there is no discernible relationship between the direction and sense of the interplanetary magnetic field and the entry times in the northern and southern lobes of the magnetotail or the entry times at various distances from its central axis, the XGSM axis. This data set is compatible with previously published work but adds significantly to observational knowledge of the subject. In broad terms, the results favor some form of an open model of the magnetotail and are inconsistent with diffusive entry of protons across a closed magnetotail field with a time constant substantially greater than a few minutes.