Up is the preposition.
The past tense of "hike up" is "hiked up." For example, "She hiked up the mountain last weekend."
The simple predicate is hiked, and the complete predicate is hiked up the mountain.
Beneath is a preposition. A little trick to determining if a word if a preposition - over the mountain, under the mountain, beside the mountain, around the mountain, through the mountain, around the mountain, above the mountain, beneath the mountain, up the mountain, down the mountain, from the mountain, to the mountain, etc. If you can't do it to the mountain, it probably isn't a preposition.
It can be either, depending on whether it has an object. "He climbed up the mountain" (preposition, object mountain) "He entered the elevator and went up" (adverb, no object).
Chasing it up mountains of steep rocks and pouncing suddenly.
"The man hiked up the tall hill""We went sledding down the hill""What looked like a hill in the distance was actually a big pile of trash"
To create a handhold to allow the climber to ascend up steep or vertical cliff faces.
I shifted gears to gain more power driving up the steep, mountain road.
An aerial railway is an enclosed carriage on a set of wires, mainly used for transportation up a steep mountain slope.
They have a soft inner padding that aids with traction, split hooves that can spread apart for balance, and sharp dewclaws that keep them from slipping.
This is usually accomplished by climbing the mountain. But be careful... It's usually a really steep climb up to the top, and then it tends to slope away rather sharply.
The preposition in the word "supply" is "up."