The organisation has called on Highland Council to block the construction in Glen Etive.
Mobile operator EE wants to put up the 10-metre mast beside the road running through the glen at the southern end of Buachaille Etive Mor.
The body representing mountain users said EE’s proposal would make some views in the area “utterly ordinary”.
In its objection, the council said alternative locations could be found in the glen which would use the backdrop of the hills to reduce the visual impact.
Its submission states: “We recognise the importance of effective mobile telecommunications, especially in the context of safety in the hills.
“However, we believe that in the case of this proposal, viable alternatives are available to the developer. We object to the proposal and would urge EE and BT Group to think again.”
Mountaineering Scotland chief executive David Gibson added: “The mast and infrastructure would render some views utterly ordinary.”
A statement issued by EE said: “Providing mobile coverage in Glen Etive is critical for search and rescue, the new Emergency Services Network and visitors to the area.”