Mt. Shasta, Lava Beds National Monument, Medicine Lake Volcano, Lassen Volcanic National Park
Earth Science 35 - Field Geology (2 units)

Jeff Tolhurst, Ph.D., Instructor
(209) 588-5235

Facebook Earth Sciences Program Page

1914 Eruption of Lassen Peak

In 1865, a pioneer named Kendall Vanhook Bumpass, who had discovered the site the year before, guided a newspaper editor interested in covering it. While showing off his discovery, Bumpass stepped on what looked to be ground but was really only a thin crust covering boiling liquid. The crust broke, his leg plunged through into the scalding muck, and his injuries were so severe his limb had to be amputated. Afterward, he reportedly said, "The descent to hell is easy."



Geology of Mt. Shasta by Bill Hirt, Ph.D.

Lava Beds National Monument
Geology of Lava Beds National Monument

Lava Beds Geology Brochure
Caves Brochure
Geology of Medicine Lake Volcano by Bill Hirt, Ph.D.

Lassen Peak National Park


Suggested Reading:

1. The Field Guide to Geology by David Lambert and the Diagram Group; Facts On File, Inc., 11 Penn Plaza, New York, NY 10001.

2. Geology by Frank H. T. Rhodes, published by St. Martin's Press 175 Fifth Ave., New York, NY, 10010,

Objectives: Given information on the geological history and the main geologic processes occurring in the Shasta, Lava Beds, Medicine Lake, Lassen region, you will be able to explain/describe the main geologic processes that have formed and continue to shape the Cascade Range in California.  You will also be able to describe some of the current geologic events and issues in the region.

Procedures: We will meet two times: 1) in class (Monday, September 21st); and for the trip (Thursday-Sunday, September 24th-27th). The pre-trip meeting will cover information on what to bring, what to expect, and what to turn in for credit. We will also cover some information on the geological background of the Cascades to prepare us for the trip. A trip itinerary will be given.

Note: Camping fees for the trip (three nights) will be approximately $6-10.00 ($20 max)depending on how many students and vehicles there are.


Thursday September 24th: We will meet at the dorms on campus so that you may have a place to leave your vehicles overnight (3 nights) for those needing to leave vehicles. Loading time will begin at 7:30 am and we will leave shortly thereafter (by 8:00 am sharp), once all heads have been counted and gear loaded. We should arrive in the Castle Crags area by early afternoon. We will drive north to Sacramento to I-5, then continue on to the Mt. Shasta area where we will make several stops to examine the geology of the Shasta area.  We will camp on the side of Mt. Shasta at approximately 5,000 feet elevation.

Friday September 25
th: We will explore more geology around Mt. Shasta, making a trip around the volcano and part of the way up its side.  We will examine evidence of debris flows, pyroclastic flows, plug domes, and other features associated with the volcano.  Then by mid-day we will head toward Lava Beds National Monument, stopping at the Klamath National Wildlife Refuge Visitor Center (briefly) on the way.  We will tour the Visitor Center at Lava Beds, then visit a couple of the caves in the Monument to examine and learn about their features.  We will camp in Lava Beds National Monument Friday night (~4,500-5,000 feet elevation).

Saturday September 26th
: We will explore the geology of Medicine Lake volcano on Saturday morning.  Medicine Lake is the largest shield volcano in the continental United States.  We will make several stops around the volcano to examine features associated with shield volcanoes (i.e. the Medicine Lake Glass Flow among others).  We will then head further south toward Mt. Lassen National Volcanic Park and spend the afternoon in and around Mt. Lassen examining features associate with strato volcanoes.  We will also stop at the Visitor Center there.  We will camp on Mt. Lassen Saturday night.

Sunday September 27th: We will explore more geology around Mt. Lassen Sunday morning and decide as a group.  We will head for Columbia College, leaving Mt. Lassen around 10:30-11 am, which should get us back to campus by around 6 or 7 pm.

What to Bring:

-- clothing for both warm and cold/wet weather
-- camping gear (tent, sleeping bag/pad, tarp, etc.)
-- food breakfast, lunch, and dinner plus snacks for each day (click here for more detail)
-- sturdy hiking/walking shoes
-- sunscreen/chapstick
-- mosquito repellent
-- sunglasses
-- a hat
-- bike helmet
-- headlamp

-- money for miscellaneous items
-- a learning log (to be turned in for credit)
-- any medications you might need
-- earplugs so that you can sleep at night
-- a camera

-- other

What to Expect:

Expect hot/warm days down at lower elevations and cold/possibly wet (thunderstorms) up at higher elevations.  Summer temperatures range from about mid to high 90's during the day to the mid to low 30's at night (we've been snowed upon!).  The weather is usually nice this time of year, but who knows what will happen! The region is prone to afternoon thunderstorms and it will be difficult to say what the weather will be like. Be prepared for a range of weather.

What to turn in for credit:

In order to assess your learning, I'll ask you to keep a learning log for the trip. You will be expected to turn this in to me at the end of the trip. This log should document the things you would like to learn before the trip as well as why you are taking the class. You should also enter into your log the things you learned about: 1) Mt. Shasta and surrounding area; 2) Lava Beds and Medicine Lake Volcano; 3) Mt. Lassen. You will be asked to make an entry at each stop on the trip as well as add an additional entry at the end of each day, reflecting on what happened during the day. A final summary of what you learned on the trip (4-5 pages) will be required for full credit. All work will be due (in my mailbox) on Monday, October 5th, by 7:30 pm in my mailbox. To summarize, the learning log should include:

  1. a description of your background with a PHOTOGRAPH of yourself

  2. a field log entry at each stop along the trip of observations and new material learned

  3. an entry in your field log at the end of each day reflecting on what your overall impressions of the day were

  4. a 4-5 page overall summary of the trip including what you learned about:
         1) the geologic story of Mt. Shasta;
         2) the geologic story of Medicine Lake Volcano and Lava Beds;
         3) the geologic story of Mt. Lassen;
         4) 8 photographs documenting important geologic phenomena;
         5) 3 hand-drawn diagrams (or computer generated by your own hand)
             depicting important geologic processes or phenomena observed

    The summary will include a 4 page minimum, 5 page maximum, type-written report. The 8 photographs may not be included on the 4-5 type-written pages. They must be referred to in the text, but each must be placed on a separate page.  Also include 3 separate diagrams in the report these, too, must each be placed on separate pages.

Grading Scheme:

A = satisfactory completion of 1-4 above with strong demonstration of understanding of geological concepts encountered on the trip; appropriate use of photos and diagrams to support concepts in the paper; paper is well organized (i.e. includes an overview of what will be discussed, a main body explaining primary concepts, and a summary/conclusion). Also, appropriate conduct and behavior expected of a college-level geology student will be factored into your grade.  (Click here to read the Student Code of Conduct from the Columbia College Catalog)

B = completion of summary without all photos and/or diagrams; less than 4-5 pages; not type-written; field log incomplete; lack of comprehension of geological concepts observed; poorly organized paper. Also, appropriate conduct and behavior expected of a college-level geology student will be factored into your grade.

C = completion of field log; no summary turned in or summary, but no field log; poor comprehension of geological concepts observed; poorly organized paper. Also, appropriate conduct and behavior expected of a college-level geology student will be factored into your grade.

D = attendance on field trip only; no field log turned in; no summary turned in. Also, appropriate conduct and behavior expected of a college-level geology student will be factored into your grade.

F = no attendance or left trip early and did not turn any work in. Also, appropriate conduct and behavior expected of a college-level geology student will be factored into your grade.

Note: I have had to add these statements based on past student behaviors: 

1) All campgrounds we stay in ask for quiet after dark.  If you (individually or  in a group at the campground) have to be asked to be quiet after 9 pm your grade will be dropped.  If you have to be asked again your grade will turn to an "F" and you will fail the course;

2) NO SMOKING during field lectures and activities.  If you cannot adhere to this requirement you should not sign up for the course.  Due to past student health issues (asthma and other lung issues) smoking can be dangerous to others around you.

That having been said, I hope we all have a good trip! Feel free to contact me at the phone number or email address above if you have any questions before or after we leave.





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