Answer: treeline

AnswerCrossword Clue
TREELINE

Limit of timber growth

TREELINE

Mountain demarcation

TREELINE

Mountains have no timber above it

TREELINE
Edge along some mountaintops
TREELINE
It's at about 9800 feet on Mount Kilimanjaro
TREELINETimberland limit
TREELINEMountainside demarcation
TREELINEWhere certain vegetation stops.
TREELINEMountain feature.
TREELINEMountain dividing point
TREELINEMilestone for mountain climbers
TREELINEArboreal border
TREELINEIt's about 2,500 feet up on Mt. McKinley
TREELINEWhere the top begins to get bare
TREELINEThe edge of the green?
TREELINETundra borderer
TREELINEFringe of the green?
TREELINECertain upper-growth limit
TREELINEForestal crown
TREELINEWhere the timber ends
TREELINELogger's cutting edge
TREELINERockies demarcation