There are some rocks, roots, and a couple switchbacks.
The Humbug Trail generally runs east/west in Yreka's Greenhorn Park. Running east to west (as mapped) results in a steady but gradual climb punctuated by short descents; running west to east starts with a short, steep climb followed by a long, easy descent for the remainder of the trail.
At the eastern end of trail, you'll find the water tower and intersections with the Lynn Skinner Memorial Trail
and Big Ditch Trail
. The Goat Trail
intersects Humbug toward the middle of the trail. At the western end of the trail, you'll meet up with the Flume Trail
and the AARP Trail
a few hundred feet before (east).
The Humbug Trail is not very technical, but there are some rocks, roots, and a couple switchbacks. Trail surface is mostly hardpack, but it has some drainage issues leading to ruts and mud in the wetter months. Humbug Trail has awesome views of the surrounding mountains in the distance and the town bellow, with multiple bench-equipped overlooks.
Humbug Trail is a popular multi-use trail, so be careful on blind corners.