The 26th International Cosmic Ray Conference was held in Salt Lake City, Utah, from August 17-25, 1999 with over 800 attendees. This book contains the invited, rapporteur, and highlight papers. These papers summarize the most exciting new results in the field of cosmic ray physics and detail their importance to the larger fields of astrophysics and high energy physics. Some of the topics included are cosmic rays, solar physics, high energy particles, neutrinos, gamma rays, astroparticle physics, cosmology, and experimental techniques.