Hiking in Lassen Volcanic National Park has all of the intrigue of a national park but the solitude and serenity of the wilderness, even at its main attractions. Warner Valley Trailhead is an access point to the adventures and surprises that lie in the south central section of the park. The trails in the Warner Valley area of the park that we were eager to check out were Boiling Springs Lake, Terminal Geyser, and Devil's Kitchen.