Based on the average frequency of encounters, the average spotting distances of encounters, the average percentage chance of an encounter being in a lair, and the average distance traversed per encounter throw, I worked up the expected number of lairs per hex.
You can use the following table to determine how many lairs will appear in each hex:
Terrain | Lairs Per Hex |
Inhabited | 1d4 |
Clear, Grass, Scrub | 1d4 |
Hills | 2d4+1 |
Woods | 2d4+1 |
Desert | 2d4+1 |
Jungle | 2d6+1 |
Mountains | 2d6+1 |
Swamp | 2d6+1 |
Each day of searching, allow one encounter throw to find a lair.