20 The Park Service WINTER CONTROL CABIN is a hundred yards east (uphill) of the road. It is used by Park Rangers on ski patrols and on the monthly winter snow-measuring trips. The latter are conducted in cooperation with the State of California Snow Survey. The depth of snow pack and the amount of water it contains determines the schedule of commercial water-use activities in the valley for the following summer. Snow packs of 20 feet representing a snowfall of over 50 feet, are common in this area. (0.4 mile) 21 Scenic view of LAKE HELEN and the western half of the REMNANTS OF COLLAPSED MT. TEHAMA. This ancestral mountain, a composite or strato-type volcano, was destroyed during the Ice Age in much the same manner as Mt. Mazama, which collapsed to form 2,000 foot deep Crater Lake. Brokeoff Mt., Mt. Diller, and Pilot Pinnacle to the south and west are remnants of Mt. Tehama. In the roadcut to the east of rounded markings are “inclusions” of an early stage of hardening of the crust of this dacite lava which was later shattered, and engulfed, and partly remelted when the molten rock from below forced its way upward. (0.3 mile) [Illustration: “Vulcan’s Face” appeared in a 1914 eruption cloud over Lassen Peak. —photo by a U. S. Forest Service Ranger] [Illustration: The Devastated Area, No. 44 in the Road Guide, is slowly recovering after eruptions in 1915 flattened trees on the northeast slope of Lassen Peak. —NPS photo by R. C. Milne] [Illustration: Bumpass Hell, the most spectacular thermal area in the Park, is 1,400 feet long and 500 feet wide. —NPS photo by R. L. Nelson] [Illustration: A self-guiding trail, starting at No. 17 in the Road Guide, leads to steaming fumeroles, hot springs and boiling mudpots. —NPS photo by R. L. Nelson] [Illustration: Landscape] BROKEOFF MT. MT. TEHAMA MT. DILLER PILOT PINNACLE SKI HEIL PEAK EAGLE PEAK LAKE HELEN 22 LASSEN PEAK TRAIL SIGN. On the southeast side of the road is the Peak Parking Area, and on the northwest side starts the trail up Lassen Peak. The Peak Trail is a well-graded climb of about 2,000 feet: from 8,500 feet to 10,457 feet in 2½ miles of hiking. It takes most persons about 4 hours for the round trip, though some take an hour more, and a few an hour less. For a pleasant hike: