Track reconstruction in heavy ion collisions with the CMS silicon tracker

The Large Hadron Collider at CERN will collide protons at \sqrtS = 14TeV and lead ions at \sqrt$\S_{NN}$. The study of heavy ion collisions is an integral part of the physics program of the Compact Muon Solenoid (CMS). Central heavy ion events at LHC energies are expected to produce a multiplicity of up to 3500 charged particles per unit of rapidity. The CMS detector features a large acceptance and high resolution silicon tracker consisting of pixel and strip detector layers. We describe the algorithms used for pattern recognition in the very high track density environment of heavy ion collisions. Detailed studies using the full detector simulation and reconstruction are presented and achieved reconstruction efficiencies, fake rates and resolutions are discussed.