Skill Level 50
The following patch bumped it to a skill level of 50. Plane of Sky patch -> Post Velious patch
It's in the Sky release patch notes.
January 20, 2000 (Plane of Sky patch)
https://groups.google.com/d/msg/alt....s/GDyzC4OScIoJ
*Druid Enhancement*
The skill cap on a Druid's tracking skill has been increased. This
change was implemented based upon general public opinion that the
former cap was far too low for the skill to be even marginally viable.