Across the West and Back Day 2: Are We Lost Yet?

We left this meandering trip report almost two weeks ago, after MOH and I had taken our short hike into the limestone at the Grassy Mountain Rest Stop. From there to Salt Lake City, we cruised while admiring the shorelines of ancient Lake Bonneville.

Lake Bonneville shorelines in the southern Lakeside Mountains, looking northeasterly from I-80 about five miles northwest of Delle, UT.

And then: Salt Lake City.

Driving into SLC can make me somewhat apprehensive unless I'm going directly to the airport, and I had already started wondering if I was getting a migraine — possibly from normal trip concerns, possibly from driving, maybe from poor sleep the night before, possibly from some other, unknown cause.

I had looked at our route on Google Maps and had looked at the interchanges and major turns in Street View. Examining the route online is not the same as having a physical map in hand while driving (or in the navigator's hand, as the case may be) — at least not for me, or at least not unless I have some ingrained or recent familiarity with the particular roads in question. The last time I'd driven (or been driven) east through SLC without turning onto I-15 to go either north or south was in 1957 when I-80 didn't exist — and the 1957 trip definitely didn't count as recent, maybe more like Ordovician, or even late Precambrian.

I knew I was looking for the turnoff from I-80 to U.S. 40 — not that far past SLC, I thought — but I don't think I'd written down the miles to the exit, and I know I hadn't written down the exit number. And for some mysterious reason I was thinking that Park City (which I've never been to, except possibly on that long ago 1957 trip) was a lot closer to SLC than it really is.

Consequently, when the interstate turned a bit to the northeast and headed upward into the fairly tight canyon of Parleys Creek, I instantly freaked and thought it was the even narrower Echo Canyon, which I remembered from coming west out of Wyoming on I-80 on a 2006 trip. I was sure I didn't want to be heading into Wyoming on I-80, so I thought I must have missed the desired exit up somewhere near Park City (!).

I turned around at the first opportunity amidst a rash of roadwork, blocked exits, and narrowed lanes.

I knew I needed a map, so we got off at what turned out to be Exit 4 on 215. We pulled into a gas station and got some gas and a relatively small scale map of Utah. It was at this point that I was sure I had a migraine — and migraines do this funny thing to your overall thinking and analysis skills.

After examining the map while experiencing fairly moderate noise, light, and motion sensitivity that caused me to have problems looking at the map and then looking anywhere else, like at the road, I decided we were on an "outer" loop around SLC that I was previously unaware of. (This "outer loop" actually consisted of I-84 from Ogden, east and southeast to I-80 at the beginning of Echo Canyon, and south and then back west into SLC on I-80, but that part of I-80 wasn't marked, neither was 215 marked, and the insert for SLC was surprisingly small and lacking in detail.) We were actually at a gas station along the 215 partial ring road, and I probably knew that fact when I had turned on to it after turning around in Parleys Canyon.

I figured all we'd have to do was get back onto this previously unheard of "outer loop" and head east or south to our desired exit onto U.S. 40 near Park City. Wrong.

The map in question.

By this time, MOH had wisely taken over the driving while I endeavored to determine our exact location. With a blur of freeway lanes, cars and trucks, and exits coming too fast to comprehend (this should have given me a clue), what I was seeing on the map (how could Alta and Snowbird already be north of us?) wasn't matching the route I'd incorrectly figured was the one we were on, and it wasn't matching my still intact knowledge of where we really were along the Wasatch.

Suddenly, the "outer" ring road turned due west, and I knew something was very wrong. I realized where we had to be (on the "inner loop" road, i.e. 215) just in time to navigate properly and direct us onto the exit for I-15 south. Whew!

At this point, we thought it would probably be just as easy to take the next road south over the Wasatch than to turn around and go back for I-80, Park City, and U.S. 40. As for this thought: not exactly correct.

View Our Crazy Route through SLC in a larger map

Because we went (unexpectedly, for sure) south on I-15, I was able to get a pretty decent, albeit somewhat grainy, shot of the Bingham Canyon copper mine.

View of the Bingham Canyon copper mine, looking west from I-15.

It has been quite a while since I've been to Bingham Canyon — and I've never had a tour into the pit itself — but I strongly recommend going to the overlook and Visitors Center (the latter of which I've never seen) when they are reopened. The overlook area has been closed since the April 10th landslide (see a pre-landslide panorama of the pit here, view Kennecott's photos of the slide here, and read about the slide on several blog posts by Dave Petley).

Looking east toward American Fork Canyon.

And so, with our most recent trip decision finally behind us, we proceeded down I-15 to the Utah S.R. 92 exit, onto 92, and into the Wasatch via the easy, wide-looking American Fork Canyon.

View Day 2: Elko, NV to Vernal, UT in a larger map

The embedded map above shows the location of the three photos in this post (and also the rest of the Day 2 photos already posted, if you move around inside the map or view it in an enlarged version).

Related Posts:
Across the West and Back Day 2: A Hike along a Limestone Ridge
Across the West and Back Day 2: Across the Salt Lake Desert
Across the West and Back Day 2: A Side Trip in West Wendover
Across the West and Back Day 2: Pequop Summit to West Wendover
Across the West and Back Day 2: Looking for an Old Roadcut
Across the West and Back: The First Day
Intro to Recent Western Loop Trip

Repost: Blackhawk landslide, California - from Pathological Geomorphology

This article was originally posted at the soon-to-be-defunct Posterous.com site, Pathological Geomorphology, and was transferred here (thanks Kyle!) to the active Pathological Geomorphology (Tumblr). My original post was a response and addition to Callan's Blackhawk landslide post on Posterous, which is now here on the Tumblr site. I've transferred the original photos, added captions, and added a Google Maps location link at the bottom. I've added the original comments (with soon-to-be-dead links to Posterous) at the bottom. Also see this related post here on LFD.

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I'm posting a few additional views of the Blackhawk Landslide in California, to emphasize the truly pathological geomorphology of the area. In the views showing slide toe and slide source, I've moved the source area farther into the mountain from the original given by San Diego State [dead (kmz) link originally sourced here]. I've done this based on prior knowledge and published maps. Basically, the entire steep northern face of Blackhawk Mountain is the slide source area.

Google Earth view showing the slide source and slide toe.

Google Earth view looking from above the toe toward the source.

Google Earth view looking from above the source toward the toe.

Additionally, there are other older landslides in the area, most notably the one sometimes called the Silver Reef landslide, which is just east of the Blackhawk. Also, many additional breccias and possible landslide deposits have been mapped in the area. The geologic maps (Big Bear City quad and Cougar Buttes quad) are really awesome, especially if you know how complex the geology really is. There are numerous thrusts from the south, placing brecciated rocks of multiple ages on usually older rocks. In at least one place, bedrock has been pushed over one of the older breccias. Or is it really bedrock?

Back in the 1980's, I mapped a large area of Blackhawk Mountain and surrounding areas at 1inch = 500 feet. I found, and so have others working in the nearby northern slopes of the San Bernardino Mountains, that if you start at the top, clearly in bedrock, sometimes brecciated, and map down, then you will be tempted to map bedrock until you are clearly in landslide debris. If you start from the top and map up, the opposite is likely to happen.

Google Earth aerial view.

Aerial view with annotated geology.

The reason for northward thrusting is the bend in the San Andreas fault, causing the westward, southward side to be pushed northward, breaking over the steepened San Bernardino Mountains in low-angle faults. The thrusts cause brecciation, and the steepening, brecciation, and low-angle faulting predisposes the area to massive sliding. Stratigraphy is somewhat retained in the slides, and gold has been mined from nicely pre-broken landslid rock of the Blackhawk Slide. Silver occurs in somewhat disturbed veins in the Silver Reef Slide.

In the annotated view, the Younger LS deposits (yellow) are Holocene or late Pleistocene; the Older LS deposists (turquoise and pink) are middle or early Pleistocene; the Moderately Old LS deposits (purple and orange) are middle or early Pleistocene; the very old debris flow fan deposit (purple) is middle or early Pleistocene; and the QT Breccias (blue and red) are Pleistocene or Pliocene.

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Lockwood DeWitt responded:

Nice! The annotated map/image at the end really help clarify the messyness of interpretation here.

over 2 years agoSilver Fox responded:

And it doesn't even show the really screwed up bedrock!

over 2 years agoKatharine North responded:

Great images, Silver Fox! I'm going back and forth between the annotated image and the non-annotated ones, looking at the landscape differently each time, picking out the details. I like your note about the effect of where you start mapping - good to remember!

over 1 year agoJosiah Gardiner liked this post.

over 1 year agoAndrew Hammonds liked this post.

over 1 year agoEmil Dibble liked this post.

Falling Rock

About a week ago after several days of warming that followed our huge snow dump of April 7th and 8th, a part of a local outcrop gave way in the middle of the night, with this large rock coming to rest at a roadside pullout.
I stopped to take pictures a day or two later, pulling across the road into another pullout away from the crumbling, cliffy limestone. You can see the hole left by the chunk that fell, a chunk that then broke into small and large pieces. And notice uphill of the exposure where the hole is: it looks like the whole lower mass may have broken loose from the upper mass at some point, perhaps before the road went through, or maybe that's a small, curvilinear fault (see first photo).
The large rock and a few of the smaller chunks, were carefully protected by orange cones and Caution Tape.
The Caution Tape has since been removed, as have many of the smaller chunks, with the large rock still sitting there in reminder of the freeze-thaw action of many years. The pullout no longer looks like a good one to use, as the back half of what remains to one side of the large hole looks unstably fractured and overhung.

A "Falling Rock" sign is posted just past the downed rock for uphill travelers through the canyon; there is no companion sign on the other side of the road for the downhill approach. 'Tis the season for roadside rockfalls, so watch where you park!

Blackhawk Landslide Links & Danger in the Mojave

I recently uploaded my first post for Pathological Geomorphology, called Blackhawk: Truly Pathological. This post was inspired first by Kyle House's announcement that the subject of the month would be mass wasting, and second by Callan Bentley's post, Blackhawk Landslide, California. While writing the post, I collected a few related links.

• Caltech, 1999 , Ge 111ab: Applied Geophysics Seminar and Field Course: with reference list for the Blackhawk Landslide area.
• Miller, F.K., with Cosette, P.M., 2004, Preliminary Geologic Map of the Big Bear City 7.5' Quadrangle, San Bernardino County, California (version 1.0): U.S. Geological Survey Open-file Report 2004-1193, 1:24,000.
• Powell, R.E., and Matti, J.C., with Cosette, P.M., 2000, Geologic Map and Digital Database of the Cougar Buttes, 7.5' Quadrangle, San Bernardino County, California (version 1.0): U.S. Geological Survey Open-file Report 00-175, 1:24,000, with description.
• Shreve, R.L., 1959, Geology and Mechanics of the Blackhawk Landslide, Lucerne Valley, California Ph.D. Thesis, California Institute of Technology, Plate 1, 1:24,000.
• U.S. Geological Survey, 2006, Geology of the San Bernardino Mountains: Western Earth Surface Processes Team of the USGS.

As I mentioned at Pathological Geomorphology, I mapped in the Blackhawk Mountain area in the mid to late 1980's while doing some gold recon and exploration for Former Mining Company. It's a very neat place to work, with complicated and fascinating geology. The area is part of one of my mapping stories, about mapping from the top down or the bottom up and how the results might differ. As far as exploration went, we bulk sampled (as have so many other outfits), we mapped and sampled on the surface and underground, and we drilled using buckets to collect all the fines. All our work resulted in a geologic but not an economic success; we eventually, rather unwillingly on my part, moved on. Another exploration geo, also formerly of Former Mining Company, went back later while at another company; he may have put a couple small deposits together for smaller-scale mining than we had been interested in.

Blackhawk, which we maybe called something else so other companies wouldn't know which area we were talking about, was probably the first area in which I decided to go ahead and carry a gun in the field. This wasn't so much because that particular area was anymore dangerous than any other part of the Mojave (or, maybe it was*), but I thought I should act like a grown person in charge of my own protection, and start doing something about it. I haven't really gotten into the dangers of the Mojave that much before on this blog. Rest assured, the dangers are almost entirely related to people: people coming out of the vast basins or valleys south of the San Andreas fault, other people known as "L.A. escapees" who have escaped the mass city scene to live somewhere out in the desert, and people walking around carrying and shooting their own guns, many of them fully auto.

I found I really didn't like carrying a gun in a holster, either on my hip, or with a shoulder strap. It's extra weight (my version at the time was a .357 Magnum revolver), and carrying it made me feel just about as awkward as leaving the thing in my truck. Either way — whether I had the gun with me, whether it was in the truck behind the seat, or whether I didn't have one at all — I'd always watch my truck from some higher vantage point for several minutes prior to heading for it, to make sure no one was hanging around waiting for me. I'd also always leave the truck already turned around and ready to head out. I still do that; turning to face out, to face your exit direction, has nothing to do with the Mojave in particular, but the Mojave is probably where I started making that one of my own personal requirements.
Here's one of my favorite, out-of-the-way parking spots in the Blackhawk Mountain area, now apparently blocked by... a landslide!

*The unsafe nature of the northern San Bernardino Mountains relates to 1) the proximity of the Blackhawk area to the millions of people living in the L.A. and San Bernardino basins to the south, and 2) the proximity of the area to the tiny, then butt-ugly berg of Lucerne Valley (Google Maps), which at the time was a haven for drug thugs**. The worst of it for me was to call home or call the office from one of the two, count 'em, phone booths in town — the one in front of the Ace Motel — only to have someone drive up almost immediately in some fancy schmancy or beat up caddy and get out and start staring at me while I was talking: pointedly and impatiently staring after zero minutes. We had car phones, but they didn't work unless you got lucky or drove way down the road toward Apple Valley.

**Our claim staker, while using the other phone booth closer to the center of this supposed town, once had some slick dudes pull up on several motorcycles while he was conducting company business on said phone. While our guy was talking on the phone, Head Biker Dude jumped off one of the bikes, glared belligerently at our guy who was trying to say, "Hey, just a minute and I'll be done." Biker Dude then pulled a heavy chain outta somewhere, and then he started swinging it around and around in circles in an obvious threat: get offa my phone or I'll bust your face!

Friendly place. Can't say as I miss the town, but the geology was, and still is, great. And if you happen to be in the area, drive the road to the top of Blackhawk Mountain, to the peak called Silver Peak (MSRMaps): views from the road and from the top are impressive. Use 4WD.