The phrase "challenging mountains" is correct and usable in written English.
It can be used to describe mountains that are difficult to climb or navigate, often in a metaphorical sense as well.
Example: "The expedition team faced many challenging mountains during their trek through the Himalayas."
Alternatives: "difficult peaks" or "formidable mountains."
Mr. Clash, an experienced mountaineer and writer at Forbes magazine, takes us up some of the world's most challenging mountains by crampon and ice ax -- and to the boundaries of endurance in both the Soviet-made jet and an Indy open-wheel racing car.
He was the first disabled climber to enter the Ice World Cup and has scaled some of the UK's most challenging mountains.
I built my skills up on the less challenging mountains so I was prepared for the tough mountains.
Within 10 minutes, I am in the reserve's wilderness of challenging mountain and seaside trails.
I took the Rolls on expressways, urban streets and challenging mountain roads.
The district offers a full program of naturalist-led hikes, challenging mountain biking climbs, family-friendly educational wildlife programs and equestrian nature trail rides.
There are 65 miles of traffic-free trails in the park, and plenty of challenging mountain biking routes, so I hope people will jump on a bike and discover places they may not otherwise see.
With mild temperatures all year round and challenging mountain hikes just steps away, it is no wonder that Vancouver is an outdoor sports haven.
Step into the wilderness and find yourself the sexual plaything of devious, dentally challenged mountain men! Bizarrely, John Boorman's anti-tourist board ad actually increased interest in the southern state, sparking a whitewater rafting boom on the Chattooga river for those coming to hear the surrounding hills echoing with the sounds of evil redneck chuckling.
The flashmob meditators were no doubt derided as hopelessly naive by the Wall Street Olympians who looked down at the motley bunch challenging their mountains of glass and steel.
Despite whatever challenges, mountains, obstacles that were in his way, he's been able to overcome it and continue to battle through".
