Diablo Range Wild: Laguna Mtn & Joseph Grant

[giantbrookie]

I had intended to do some North Sierra fishing into November but my schedule and fall storms nixed that. In the meantime I shifted to "off season" geology hiking mode.

Part I. Laguna Mtn Recreation Area
The first trip was part of teaching a geologic mapping exercise for my structural geology class at Fresno State. My usual area (Sunol Regional Wilderness, SE Bay Area, NW Diablo Range) was closed owing to fire damage and its aftermath, plus there were some issues with camping. Taking the advice of a really sharp new graduate student, the class headed to the Laguna Mountain recreation area, E of King City (or W of Coalinga, depending on your point of view). We were there from Nov. 12-15. There are two campgrounds. They are primitive (no running water and pit toilets only) but they are clean and spacious. The elevations, by Diablo Range standards, are fairly high. We were camped at an elevation of about 2900' and the high point of the area, Laguna Mtn is a bit over 4500'. There are several maintained trails, some of which are essentially dirt roads. There is a rugged canyon, called The Gorge, which we tried to force (ie clamber up, off trail). This worked until we got to the dry Laguna Falls, which must be a pretty spectacular place when the water is running (there is a gorgeous photo of it on the recreation area brochure).

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We did this on day 2 (Nov 13) and by the time we got boxed in (had already climbed past one or two cliff outs) we were running out of time to do the big detour necessary to climb by Laguna Falls plus both me and my grad student had reinjured our knees, so we weren't in our best off trail scrambling mode.

Nov. 14 the 3rd of the 4 days I figured on exploring to the southern edge of the map area I had assigned to the students: this was the summit of Laguna Mtn.

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From a geologic standpoint this turned out to be a waste of time, but the fact that all the students more or less summited (it's a rounded summit and they stopped about 1/4 mi and 50' elev short of the true summit after climbing the most difficult stuff) testifies to their adventurous spirit. The last part of the ascent is by a use trail that winds through the brush. We made two attempts because we were mislead by some logs placed across the real use trail by peak baggers (apparently this is some local peak bagging target) who apparently prefer a route that went east of the limit of what I had put on the students' topo base. In any case we tried to follow the peak bagger's route and found ourselves in horrible brush. After several really bad passages we found ourselves totally hemmed in about 200' below the summit, so we turned back. It was getting a bit late and I told the students we really hadn't seen much geology beyond where we'd gone the day before so I advised aborting the summit climb. The students insisted on finishing the climb though, so when we got back to the "split" where logs had been laid across the "real" goat trail (which is the one shown on the recreation area topo map) we took the "real" trail back up the climbed the mountain. There was a logical stopping place after the main difficulties had been surmounted and as the students rested I limped up to the top (the knee was in pretty bad shape from the injury the day before).

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One of the rock samples I picked up at the summit turned out to be one of the most important research samples I've ever collected, but I wouldn't know that until I returned to campus, cut thin sections, and examined it under the microscope. During the descent, my knee blew out again when I slipped, so I was in a world of hurt hiking the rest of the way out. It was dark by the time we all made it back to the camp (which was also our kickoff point). All told (counting the detour) the hike was something like 8 miles round trip with 3200' of elevation gain which made it the hardest hike done by a Fresno State geology class in modern history.


Part II. Joseph Grant County Park to the Arroyo Hondo canyon.
After two weeks resting the tormented right knee I figured it was good enough to road test with a bit of a run, so I took a 2 mile run Sunday before last and it went off pain free (including no pain afterwards). At that point I figured I could do another crazy geology hike, this time bringing along a Bay Area geologic hiking companion, given that this hike was not one I wanted to try alone. The target for the Friday Dec. 4 geologic exploration was the bottom of one of the most savage canyons in the Diablo Range, the canyon of the Arroyo Hondo, N of Mt Hamilton. I had been told of this place over 30 years ago by a geologist who advised me to check it out, telling me that I was one of the few geologists physically able and crazy enough to try it. I didn't have a scientific motivation to go back then, whereas do now, so I've been thinking of this place for awhile. I thought to exploit the SCU burn, thinking that it would have cleared some brush off the descent. To hit the public part of this canyon you have to go in via Joseph Grant County Park (on the Mt Hamilton Rd): it is about a 4.5 mi hike with something like 1600-1700' of gain to the kickoff point on the rim (at least to the kickoff point I tried).

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This all went off OK but I lost concentration at one point in the descent and injured the right knee again, about 700' above the bottom.

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At 400' above the bottom things really start getting serious and my friend said it exceeded his sketch tolerance, so I gave it a go the rest of the way, only to throw in the towel when my own sketch tolerance topped out 150' from the bottom.

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Did trying this on a bad knee influence my decision? Maybe, but I think it would have been wise to turn around at the point even if I was 100 percent.

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Would the geology have been worth the trouble if I had made it down? Doubtful, based on what I could see, but you never know.

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The best exposures are in fact in the bottoms of canyons like this but I don't think the sort of geologic relationships I was looking for were there, based on what I could see.

Over winter break I'm already scheming on potentially better canyon climbs (but not quite as nasty as this one), with the top targets being in Henry Coe. I will also plan to return to Laguna Mtn and tie up some loose ends. And, of course, there will also be coastal fishing adventures.

[balzaccom]

Cool! I grew up in Coalinga (at least for a few years) and will have to check this place out. Looks like your group had some good adventures

[Wandering Daisy]

Do you have any advise on how to stay safe on steep slopes in the coast range, given its tendency to instability? My impression is that the first few days after a major storm should be avoided. Also may be some issues with recent fires and subsequent rains. I have been taught some very basic slope stability science but am far from an expert. Almost 50 years ago, a family friend's daughter was hiking on a coastal cliff in Washington, and the cliff collapsed, killing the girl. That has hunted me for all these years.

Henry Coe has some very steep slopes, but brush seems to be the major problem once you get off the trails/roads. There are some big oak trees on some of the steep slopes and I suppose one could rappel into those canyons. There is a very nice waterfall near Coit Lake, Pecheco Falls. It is very similar to the photo you show of the waterfall on your first trip. You would also find Cabin Creek interesting.

[giantbrookie]

Do you have any advise on how to stay safe on steep slopes in the coast range, given its tendency to instability? My impression is that the first few days after a major storm should be avoided. Also may be some issues with recent fires and subsequent rains. I have been taught some very basic slope stability science but am far from an expert. Almost 50 years ago, a family friend's daughter was hiking on a coastal cliff in Washington, and the cliff collapsed, killing the girl. That has hunted me for all these years.

Henry Coe has some very steep slopes, but brush seems to be the major problem once you get off the trails/roads. There are some big oak trees on some of the steep slopes and I suppose one could rappel into those canyons. There is a very nice waterfall near Coit Lake, Pecheco Falls. It is very similar to the photo you show of the waterfall on your first trip. You would also find Cabin Creek interesting.

I don't think large-scale slope movements are an extra menace to Coast Range hikers outside of the coastal cliffs where large-scale failures have been deadly. A lot of this is random, although climbing on some of the looser coastal cliffs is a bad idea--a few years back and young woman was killed clambering around on the cliffs of Ft Funston (southern coastline of San Francisco) which are made of loosely consolidated Pleistocene Merced Fm clastics. A couple of winters ago there was this huge collapse of a sea cliff in the northern part of Marin Headlands (Tennessee Cove area). It was a part of the coastline that hikers visit but fortunately nobody was hiking or picnicking beneath when this thing collapsed (I recall this was caught on video by a hiker who was at a safe distance). Hazard from big bedrock slides or debris flows is certainly higher during the winter and during heavy storms. One nice winter day I visited a sea cliff exposure at Black Sand Beach in Marin Headlands with my daughter and photographed some geologic relationships with my daughter for scale (this ended up as a photo in one of my papers). I had wanted to climb off the beach a bit but I was nursing a knee injury at the time and figured I'd come back in a couple of weeks when my knee felt better. A big storm came in a week later and when I returned I found those outcrops buried by a debris flow. This is one of two places that I've photographed at the base of coastal cliffs that were buried by subsequent slides; the other one is along my favorite (geologic) coastal stretch S of the Russian River (and that particular pocket beach is my no. 1 saltwater fishing spot).

There are a few off trail hiking hazards that I think are in fact different than those we encounter in the Sierra. Most bedrock of the Coast Ranges is no worse than the metamorphic rocks in the High Sierra but additional issues are some of the steep grassy slopes. To folks accustomed to bedrock cliffs and steep snow being the only sorts of things one can take a long damaging fall on, some of the steep grassy stuff can look benign, but above a certain slope angle those slopes can be potentially lethal. I don't know of anyone who has been killed on that sort of slope in the Coast Ranges but there is at least one geologist I know who was killed by a slip on such a slope in the Alps (well known petrologist, celebrating his 60th birthday slipped on such a slope and kept going and ended up flying off a cliff at the bottom of the slope). Once when I was leading an international field trip along the SF coast my wife took a short cut leaving the beach that led up a steep grassy slope. Before I could stop the group, lots of folks followed her. When we reached the top an Italian PhD student scolded me saying that her advisor was intensive care back home after a fall on a slope that looked just like that. Those steep grassy slopes get especially bad in the drier months when the soil beneath becomes baked and hard and the dried grass is matted down forming a slippery surface atop the already treacherous hard ground (like marbles on a steep slope). I have come to avoid such slopes, or to cross them only on good cattle paths. For many of the steep soil-covered slopes the best time to climb on them, if one must, is actually during the wet season when the ground becomes softer and I can kick steps into them. The Arroyo Hondo descent of last Friday would have been way harder among normal dry conditions such as those I hiked in, but I got a big break because pigs had dug up everything. It was the most widespread destruction I've ever seen (and I've seen a lot of pig-ravaged slopes in my time) and it broke up the normally hard ground and made it pretty easy to descend. I didn't have that advantage on the final 400' of descent, though.

Getting back to C. Range hazards, rockfall in some areas really ramps up in rainstorms, although I think this is the case in other mountainous areas, too. About three winters ago I was looking at geology with a Japanese petrology friend along Mines Road S of Livermore on a long drive that took us over Mt Hamilton and down the other side. I really didn't like the idea of stopping to look at roadcuts there. I pretty much stood watch as my buddy looked at the rocks so as to give him warning as another rock came bouncing down. Lots of that stuff ended up on the road, too, making driving hazardous, especially at the speed my buddy was driving. He somehow managed to avoid hitting a rock in the road, oncoming traffic , or driving off of the road until the worst was over and we were descending through Joseph Grant Park. At that point he missed the road, drove into the roadside ditch, and blew out the right front tire, which was changed in the Grant Lake parking lot, the trailhead for last Friday's hike; that was in fact the last time I'd been there.

[Wandering Daisy]

Thanks for the information! I had not thought of slippery grass. I have used crampons in the past on slippery steep vegetated slopes and to walk wet slippery logs. I wonder if micro-spikes would be useful if off-trail on the steep coast range slopes? I also have run into ball-bearing sands on steep passes in the Sierra where if I had crampons, I would have used them.