From The Stargate Omnipedia
One of many S.G.C. units deployed out of Cheyenne Mountain.
Members of SG-13 include (or have included):
David Dixon (Team Leader)
Heroes, Part 1 - SG-13 travels to P3X-666 to investigate a former Ancient planet, but encounter a Goa'uld probe instead.
Heroes, Part 2 - Pinned down, SG-13 is aided by several other units as they attempt to fight off Anubis's forces.