Tuesday, June 15, 2010

Finding a Thesis: Pole Line Road

I first drove by the then undiscovered Paradise Peak gold deposit way back in 1976 when searching for a thesis area.

Photo: Paradise Peak Mine (inactive) as seen from the Pole Line Road, 2008.
I cruised into Gabbs from the north, after driving down from Battle Mountain, where I had already checked on some possible thesis areas. I came via old Highway 8A, Highway 50, and old Highway 23.

Between Battle Mountain and Gabbs, I had gone from an area of good, detailed 15-minute (1:62,500 scale) and 7.5-minute (1:24,000 scale) topographic maps to the middle-of-nowhere area in Nevada where only 2-degree map sheets (1:250,000 scale) were available. I wasn’t used to using 2° AMS sheets, and the sudden switch from one venue to the other left me somewhat confused: my mind hadn't made the scale switch well at all. What I didn’t know then, but do know now, is that the Tonopah 2° sheet showed roads that were no longer in use; it showed roads that, even if I had found them, were probably not drivable in an Opel; and it failed to show new roads accurately, or sometimes at all.
This explanation is really a poor excuse for a geologist who got lost near Gabbs, trying but never finding a certain road while using a topo map, a skill at which geologists, including myself, excel.

Photo looking southwest toward the Cedar Mountains on the left and the Gabbs Valley Range and Pilot Mountains on the right.
On my quest to find some silver prospects and old mines in the Cedar Mountains south of Gabbs, I started just a few miles southwest of Gabbs on the paved Gabbs Valley Road (then S.R. 23, now S.R. 361) which goes from Middlegate Junction through Gabbs and on to Luning. From pavement, I turned to go south on what is called “The Pole Line Road." The Pole Line Road (C.R. 89) was and still is a major dirt road between Gabbs and Tonopah.

I measured the miles on my map, then headed south until my odometer said I should turn right and southwest into the Cedar Mountains. There was no road. I examined the map for a second time. The topography seemed quite vague and generalized, I wasn’t able to tell where I was or where I was supposed to be, and the Cedar Mountains looked farther away than they appeared on the map. I knew that topo maps don’t lie, and realizing that something — but what? — was wrong, I turned around and went back to the junction of Pole Line Road with Highway 23, and started over, once again driving south toward my elusive goal.

Looking at the photo showing the Cedar Mountains and the Gabbs Valley Range behind them, it's possible that I mistook the higher Gabbs Valley Range for the Cedar Mountains. The Gabbs Valley Range would not have been visible on the Tonopah AMS sheet, only on the adjacent Walker Lake sheet to the west.

Tonopah and Walker Lake 2° sheets from the USGS via MSRMaps.
Realizing that I was essentially lost, without being really lost, I kept turning around to drive back to the northern beginning of the Pole Line Road at its junction with the paved Gabbs Valley Road. I could pinpoint my location while at that junction, so I drove back to it at least twice, possibly three or more times, in hopes of recalibrating my miles and my addled sense of scale.

Prior to my last reversal, I drove west on a dirt road that seemed to point toward some distant hills or mountains that I hoped were the Cedar Mountains, and which probably weren't. I drove a little ways — less than a mile, in fact — and realized that my chosen route wasn't going to do what I wanted it to do. It either was too obviously jeep-trail-like for my Opel, or it turned in the wrong direction. I stopped at an old headframe located on the north side of the road and on the south side of a hill or knob, and turned back toward the Pole Line Road. My stopping point may have been the headframe to the mercury mine on the south side of what would later become the Paradise Peak ore deposit, after it was discovered by FMC Gold Company in 1983.

Had I turned around at the undiscovered Paradise Peak gold deposit? Who knows. [I could also have been at the Gold Ledge Mine to the north; and if I was, it would have meant that I was measuring 6-mile townships on the AMS sheet as one-mile sections.]

After getting back to the Pole Line, I drove north for what turned out to be one last time, making my way toward the junction in order to regain my bearings. Before getting very far, two unfamiliar animals crossed from right to left in front of my car. I slowed so I could see them better, thinking they were marmots or some kind of rock chuck. As I got about even with them, they gave up on crossing the road in favor of turning around, baring their sharp pointy teeth at my car, and hissing. They lunged at my left front tire and set about trying to attack the tire!

After hanging my head out the window and watching these fierce savages tentatively but repeatedly strike at my tire for a while — they never got quite close enough to actually claw or bite it — I decided to blow off the whole area. I turned south and hastily escaped toward Tonopah. I found out later that I'd had my first run in with two feisty badgers.

To be continued...

A Bit About 2° Sheets:
Two-degree topo sheets, each of which covers an area consisting of 1 degree of longitude by 2 degrees of latitude, are sometimes called "AMS sheets" because they were originally mapped by the Army Mapping Service (now NGA) instead of by the U.S. Geological Survey. Two-fifty thou sheets (as they are also called) often show roads that don’t exist any more. Old dirt roads that that are barely visible on the ground, and which may not be drivable, can look like main roads on an AMS sheet. New roads may not be shown at all.

The "new" Tonopah sheet I have in my possesion is dated 1956, revised 1971; the Walker Lake sheet is dated 1957, revised 1969. In 1976, some parts of Nevada were covered only by these AMS, 2-degree-scale topographic maps.

A Bit About 15' Topo Quads:
Some of the old 15-minute maps are topographically a little inaccurate, but many are topographically more precise than newer maps being printed today, especially when it comes to showing old mines and prospects, some of which are inconveniently left off some of the new topo series (1:24,000 and 1:100,000 maps, I'm looking at you).


montoya said...

One year later I just had a look at this, we are going up the same way and then cutting over to Berlin to look at the park and the ruins. Thanks for the caution on the differences in these maps. It certainly makes an impression when you are in the middle of nowhere and your map lets you down... especially with such exploration expertise and experience as yours, Silver Fox. Thanks again.

Silver Fox said...

Have a great trip!

Mike b said...

I still travel with a Nevada Road atlas, black and white and peak elevations only. But it has sections, old roads and old mines. Like you in the Opel, I'm careful to look out the window occasionally to check the road I am on. And to verify it still exists..

Silver Fox said...

Sometimes, in some places, and in some ways, the old maps can be better. But not when they tell you to cross a valley on what turns out to be a road that was great in its day, is washed out at every alluvial fan rill, and when the main road is now on the other side of the valley - if only you knew.

Having the old mines on a map is quite handy! Some of the original 15-minute maps are great for that.