Griswold Hills East P500
Griswold BM P750

Wed, Mar 12, 2014
Griswold BM
Story Photos / Slideshow Maps: 1 2 GPX Profile

I had returned to Panoche Valley in the Diablo Range only two days following my previous visit. On my bike ride through the adjacent Tumey Hills I had spied both summits I would tackle today and noted the terrain did not look difficult. My only real concern was how to reach them. Most of the Griswold Hills lie on BLM lands, but access from a public road appears to only be had at one point from the west along New Idria Rd and would make for a very difficult trans-range traverse to reach the two peaks on the east side. Approaching from the north in Panoche Valley or the south from Vallecitos requires crossing active private ranchlands in order to reach BLM lands. But with a more careful perusal of the maps I hit upon the idea of approaching via Silver Creek off Panoche Rd. This would start off on BLM land and only cross private property well away from any pavement or ranch building. This would allow me to do it safely during the daytime to enjoy the brief springtime green that had come to these desert ranges with the recent rains. The outing would be much shorter than the Tumey Hills visit, allowing me to explore this part of the range on foot rather than by bike, still covering some 16 miles and getting me back home in time for dinner.

For the second time in two days I made the daring crossing of Panoche Creek where it crosses Panoche Rd (not so daring with low water levels) - a little intimidating in a low-clearance vehicle but fairly safe - to reach my start near Silver Creek around 9a. Silver Creek itself had far less water than Panoche Creek, in fact there were only a few muddy puddles at the start and a trickle of water flowing in the far southern reaches of the creek, but most all of five or six miles in between were bone dry. An old ranch road, much deteriorated follows along the creek drainage, crossing it a number of times. I had some difficulty locating it in the beginning which led to some unnecessary crawling through brush, but on the way back I had no such issues. Following up the creek one can view numerous locations where cliffs show evidence of ancient seabeds having been uplifted and then eroded by the creek. Other slopes along the drainage show the tell-tale pattern of heavy terracing from cattle that have extensively grazed these lands for years despite their poor yield. Some places along the creek have heavy brush and some flowers, but most of the area is desert-like. Lying in the rain shadow of the main crest, these eastside hills get very little precipitation in any given year.

After about two miles along the creek I turned right and started up out of the drainage following a cowpath along a ridgeline leading to higher portions of the range. As I climbed out of the drainage I was treated to more sweeping views of Silver Creek and the surrounding countryside. Tumey Hills rise to the southeast across Silver Creek, with the Panoche Hills to the north across Panoche Creek. As I climbed the ridge I came across a fenceline that led higher to a section of an old road that once led to an oil well marked on the topo map. There is no equipment found at the site, just the end of the road at a saddle. From here, a cow trail leads higher along the continuing ridgeline for the last mile to the summit of Griswold Hills East.

It was just after 11a when I reached the summit, a rounded knob (as are all the hills in these ranges). One can look west across the Griswold Hills to the highpoint on the other side, northwest across the Panoche Valley, east to Tumey Hills and south to the Diablo Range highpoint at San Benito Mtn. Coming up from the west is a ranch road going over the summit and heading south which I would be able to follow all the way to the second summit at Griswold BM. Some of this goes through private property but there are no fences here to delineate it from the BLM lands and chances of running into anyone seem exceedingly slim. I dropped south off the road following the dirt road to a low saddle before it starts to climb back up again. There are several water troughs fed by a large plastic water tank located on an adjacent hilltop, but the system has fallen into disrepair and gone unused for some time. After topping out at just over 3,000ft along the ridge I had my first view of Griswold BM (barely 3,100ft) behind it to the south, across a pasture in a shallow valley. I dropped down about 250ft into this pasture before climbing back up to Griswold BM, a more direct approach than following the ridgeline as it curves in an arc to the west.

It was noon when I reached the top, finding the remains of an old survey tower and the benchmark as expected. I could look southwest across Vallecitos, the valley separating the Griswold Hills from San Benito Mtn. The topo map shows the Vallecitos Oil Fields across the southern part of the Griswold Hills, but if there was anything producing oil in the area it was completely lost on me - I saw nothing but more evidence of grazing taking place in the area. I had made good time in reaching the outermost edge of my hike in three hours and decided to take an alternative return down the length of Silver Creek. To reach its southern end I would have to go a few miles out of my way, but this was not a problem since I wasn't pressed for time. I followed another road east along the southern bank of a side valley that feeds into the Silver Creek drainage. In addition to more unused water troughs, I came across some fossil shells lying along the roadway, more evidence of the hills watery past as a seafloor.

As I neared Silver Creek, I left the road to avoid a circuitous detour, following an easy descent down a side ridge, part of which followed an old fenceline, long in disuse. At the creek I fould some water trickling from a nearby spring, but it didn't look very inviting. In fact the area along the creek resembled a cattle graveyard - there was the nearly full skeleton of a calf along with the partial remains of other cattle, some half dozen skulls among them. Whether this was natural attrition from a ferral herd or the work of poisonous waters was unknown, but it seemed safe to assume the waters were tainted. I spent the next several hours wandering down the length of Silver Creek taking in a variety of additional sights it had to offer. There were some surprisingly green sections, others with new shoots just starting, an occasional mushroom poking its head up, dry mud flats, bird nests in the cliffs along the banks, a graffiti wall, old water works, and more. I followed much of the old road during this time, bypassing washed out sections and losing it once or twice.

It was 3p by the time I returned to the van along Panoche Rd, making for a six-hour outing. As I was driving back to San Jose through Panoche Valley (noticing the anti-solar signs at various ranches), I was making plans for a third visit this week - seems I still hadn't had enough of the area and was eager to come back for more...

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