The unique title of ranger-general of Silvermoon (also known as the Ranger-General of Silvermoon or the Ranger General of Quel'Thalas) is given to the commander of the Farstriders — the blood elf rangers of Quel'Thalas. The ranger-general is also the commander of all of Quel'Thalas' military forces. During the Second and Third Wars, the ranger-general of Silvermoon was Sylvanas Windrunner. Following her death at the hands of Prince Arthas, the Farstriders elected Halduron Brightwing as its new ranger-general.
Lor'themar Theron was second-in-command to Sylvanas Windrunner during the Third War and some have speculated that he became the new ranger-general after her death. However, there isn't any source that specifically states this.