A continuous water column is shown to exist in the pore of a potassium channel. Quantum calculations (HF/6-31G∗) were performed on the Kv1.2 channel (pdb:2A79/3Lut), giving the structure of the pore with 50 water molecules. Calculations were done with 0, 1, or 2 ions. The protein from the PVPV intracellular gating region to the entrance to the selectivity filter, including the tyrosine of the TVGYG sequence (≈14.1 A) was included, with water extending slightly past the region. Results show how the ion(s) restructure(s) the water; water structure largely controls interaction of ions with one another and with the protein. We had previously posited that there must be an oscillating gate including water, which changes structure with ion position (Int’l J. Molec. Struct., 2012, 13, 1680); newly calculated structures correspond to the previously hypothetical states. These results also indicate the presence of two other local minima for the ion, one in the cavity, one at the entrance to the selectivity filter, where the protein replaces water in solvating the ion. A single ion there is sufficiently distant that the gate water cluster returns to its original form. There is some charge transfer to the ion from unshared electron pairs on oxygen. Finally, we determine the water cluster structure's relation to boundary protein. The water column in the pore is continuous, and energy barriers for an ion moving up in the pore appear compatible with observed conductivity in the channel. Thus, interactions between ions are largely modulated by water structure interacting with protein structure, not simply electrostatics.