A no-vehicle gravel road goes about 2/3 if the way Mount Peak, our baby volcano at the edge of town. I had made the steep ascent on the trail trike and Quadraped before, but this time explored the forest trails from the top end of the road on up. There was a lot more climbing, and I gave out near the top. On the final hundred feet, you have to pick your way among large rocks up an even steeper incline.
The trail trike has a Mountain Tamer 18 tooth front chainring, with a 28 tooth rear cog and Dual Drive in low range. That takes it down to about 10 gear inches. Traction is provided by a 26" knobby tire with the pressure dropped to about 20 pounds. I could have made it further with a couple more gear inches, though traction was approaching its limit.