The structure of the (111) plane of gold single crystals growing from the vapor, deposited at a rate equivalent to 0.026±0.005 monolayers∕second, has been studied using carbon replicas and electron microscopy, electron and x‐ray reflection diffraction. Below a temperature of 750°K, crystallites of gold develop on the surface, sometimes with preferred orientation. Somewhat above this temperature, extensive surface step systems and oriented trigonal growth centers are observed. The crystallographic orientation of the steps and growth centers, as well as reflection x‐ray diffraction patterns from these surfaces, are evidence that the deposited gold atoms participate in growth of the substrate crystal at temperatures above 750°K. Development of these trigonal growth centers is described in terms of a simple model in which diffusing atoms are preferentially incorporated into growth centers at sites with particular coordination arrangements, i.e., such that the growth centers preferentially expose particular facets. Existence of oriented step systems and growth centers implies that adsorbed gold atoms diffusing on the surface are reversibly captured at steps under these growth conditions. Consequently, the activation energy for surface diffusion includes the energy for dissociation of atoms from steps to adsorbed positions on an atomically smooth portion of the surface. An upper bound for the activation energy for surface diffusion is concluded to be approximately 1.7 eV for atoms adsorbed on the (111) plane. The activation energy for motion of an atom along a step is estimated to be approximately equal to or greater than 0.7 eV.