En montée vs. en amont

The French expressions 'en montée' and 'en amont' both relate to upward movement or position, but they are used in different contexts and have distinct nuances.

En montée

'En montée' specifically refers to an uphill slope or incline. It is commonly used to describe physical movement or terrain that goes upward.
La route est en montée sur plusieurs kilomètres.
(The road goes uphill for several kilometers.)
Le cycliste a du mal à pédaler en montée.
(The cyclist is struggling to pedal uphill.)
Cette partie du parcours est en montée constante.
(This part of the course is a constant uphill climb.)

En amont

'En amont' has a broader meaning. While it can sometimes be translated as 'uphill', it more accurately means 'upstream' or 'earlier in a process'. It's often used figuratively to describe something that comes before or is higher up in a sequence or hierarchy.
Le village est situé en amont de la rivière.
(The village is located upstream of the river.)
Il faut résoudre ce problème en amont du processus de production.
(This problem needs to be solved earlier in the production process.)
Les décisions sont prises en amont par la direction.
(Decisions are made at a higher level by management.)

Summary

While 'en montée' specifically refers to an uphill physical slope or movement, 'en amont' has a broader meaning that can include upstream locations, earlier stages in a process, or higher positions in a hierarchy. 'En montée' is more concrete and physical, whereas 'en amont' can be used both literally and figuratively in various contexts.