The phrase "a difficult trek" is correct and usable in written English.
You can use it to describe a challenging journey or hike, often in a physical or metaphorical sense.
Example: "The group prepared for a difficult trek through the mountains, knowing it would test their endurance and resolve."
Alternatives: "a challenging journey" or "a tough hike."
The lack of a disabled parking space often leaves him a choice between a difficult trek through the parking lot or returning home to ask his wife to drive him back to the store.
Richardson's men, unprepared for the snow, made a difficult trek back to the lowlands.
Rugged mountains and rocky plains make it a difficult trek for people, but well-suited for donkeys and drones.
Though it is not a difficult trek, the altitude at Dolma La pass, 18,500 feet, adds foreboding to the sanctity of this place.
Hertel de Rouville's band killed or took prisoner many of the townsfolk, returning to Canada on a difficult trek in which a number of the prisoners died; many of the surviving captives were adopted into Indian communities afterward.
She loves going to school though it means a long difficult trek through very hilly terrain.
Applications must be made in person, which means a long and difficult trek from the Rockaways and other storm-damaged areas.
"Many children in this part of Zambia cover very long distances between their villages and their schools and it's a dangerous and difficult trek".
Several Sherpas at Mount Everest's base camp — where foreign climbers wait for the right weather conditions to set out on the difficult trek — launched an immediate boycott of the mountain, threatening to put the entire climbing season on hold, which is a lucrative source of revenue for this poor country.
There are a lot of us wandering this difficult trek.
The adolescent's difficult trek took him to Mugunga1, a site for internally displaced persons (IDPs) on the outskirts of North Kivu's capital city of Goma, where he is now on his own.
