The LDEF (Long Duration Exposure Facility) cratering record suggests a significant population of large interplanetary dust particles (100 μm diameter and greater) near 1 AU, implying that particles with diameters as large as 500 μm may be significant sources of the infrared flux that we receive from the asteroid belt. However, integration of the full equations of motion of these very large particles, including radiation pressure, Poynting-Robertson drag and solar-wind drag, is extremely numerically intensive. As a result, our previous efforts to determine the dynamical history of main-belt, asteroidal dust particles were limited to particles with diameters less than 100 μm. We have recently developed an integration code based on a modified symplectic algorithm which, when combined with the availability of cheap, fast processors, provides us with the opportunity to extend our models of the zodiacal cloud to include this important, and possibly dominant, large particle population. Here, we present initial results from our numerical simulations.