Survey of Key Saddles for 3 P2000s in California:

Palomar Mountain, Cuyamaca Peak, and Whale Peak

submitted by Edward Earl
January 16, 2005
Summary:

The experts weigh in on which peak in San Diego County gets the most prominence.  The Key Saddles of Palomar, Cuyamaca and Whale are professionally surveyed.  The result is, unfortunately, still too close to call.  Then I weigh in on the benchmark datasheets, which slightly changes  the elevation of Palomar Mtn.

The combined results are posted on the California P2000s Page.
Edward's Report:

Richard Carey and I spent much of a Saturday performing what is perhaps the first operation of its kind: a formal survey of the elevations of the key saddles of the three most prominent peaks in San Diego county: Cuyamaca Peak (saddle is Teofulio Summit), Palomar Mountain (saddle is Sunshine Summit), and Whale Peak (saddle is 1 mile west of Blair Valley). The surveys were performed by a two-man team using real surveying equipment, with one person sighting through a telescope on a tripod and the other holding an upright graduated rod. It was fairly good fortune that all three saddles are on state or county highways and had a benchmark conveniently located nearby.  All three surveys were conducted using a series of level sightings from the benchmark to the exact saddle.

First to go was Sunshine Summit, shown here: http://www.topozone.com/map.asp?lat=33.35167&lon=-116.73778  Starting at the 3272' BM about 800' NW of the saddle, we determined an elevation of 3284' for the saddle, which is in an open grassy field near a wooden utility pole. Since Palomar Mtn has a summit of 6140', its prominence is therefore 2856'. This figure is good to within one foot.

Teofulio Summit, http://www.topozone.com/map.asp?lat=33.205&lon=-116.603, the Cuyamaca Peak saddle, presented some challenges. The nearest bench mark was the 3557' BM about 2000' N of the saddle, and the BM was about 90 to 100 feet lower than the saddle. Richard's rod was only 13 feet high, so we had to accumulate a series of 8 or 9 sightings, which took some time. To complicate matters more, the roadbed is cut about 10' down from the natural how high it was. We determined an elevation of 3646' for the present-day road saddle. The prior natural saddle is probably very close to the west side of the cut, as the embankment on that side is not as high as on the east side and the "ridge crest" is near level on that side, whereas the terrain rises away more steeply from the rim of the embankment on the east side. We could only guess the exact height of the natural saddle, but our best estimate based on the slope of the remaining natural ground was that it is about 1 foot lower than the highest point on the west lip. The elevation of that point is 3657'. With a 6512' summit for Cuyamaca, its prominence is 2855' for the natural saddle, or 2866' for the roadcut saddle.

Our third and final survey of the day was the key saddle of Whale Peak, saddle shown here:
http://www.topozone.com/map.asp?lat=33.35167&lon=-116.73778  We started at the 2642' BM E of the saddle. Despite that fact that the distance was about the same as at Teofulio Summit, we required far fewer sightings because of the minimal difference in elevation. One sighting, however, was so long (about 1/4 mile) that it was difficult to read the numbers on the rod. We determined an elevation of 2649' for this saddle, and the prominence of Whale Peak is 2700', within one foot.

The long-standing battle between Cuyamaca and Palomar as the county's most prominent point has only gotten tighter. For several years, ever since I first compiled the San Diego county 1000' prom list, I considered Cuyamaca to be the county's most prominent point. I am quite familiar with its prominence saddle, which I have driven through dozens of times. The highest point on the road is marked by a sign, "Teofulio Summit, Elev 3636". When I identified Teofulio Summit as Cuyamaca's prominence saddle, I noted a 3636' spot elevation, recalled the roadsign, and considered the saddle to have an exact elevation of 3636'. So Cuyamaca prom = 6512 - 3636 = 2876. Palomar, on the other hand, has a summit elevation of 6140 and a saddle in the 3280 to 3320 contour interval, so its prom is 2820 to 2860. Cuyamaca wins, case closed.

Then sharp-eyed Andy Martin noted two things. 1) The 3636' spot elevation isn't exactly at the saddle, but a couple hundred feet south, and it probably refers to either a dirt road that branches off there, or a point where the highway crosses a section boundary. 2) The highway climbs above the 3640' contour, and the saddle is at least this high, possibly as high as 3680'. So Cuyamaca's clean prominence is demoted to a mere 2832', overlapping Palomar's possible prominence. The exact elevation of Teofulio Summit is probably near the low side of its contour interval. Cuyamaca was still favored but no longer the sure winner.

I had hoped that my surveys with Richard would settle the matter, but unfortunately the effect was the opposite, and things got even murkier. Using the roadbed saddle, Cuyamaca's prominence is 2866, still enough to beat Palomar by 10', which is well outside the error of our measurements.  But if one uses the natural saddle, Cuyamaca's prominence erodes to a mere 2855', and Palomar nominally beats this by one foot. But that is within the error of our measurements since they were performed starting at benchmarks whose elevation is only given to the nearest foot, and there is a couple more feet of error due to the fact that the natural saddle has been bulldozed away and one can only guess what its elevation was. If one uses the natural saddle to define Cuyamaca's prominence, then the race between Cuyamaca and Palomar is too close to call.

I had long believed that one would need to climb only Cuyamaca to be able to claim to have climbed San Diego county's most prominent point, but now I have updated the CA county prom list to show both Cuyamaca and Palomar. As the world's premier compiler of prominence lists by county, I am quite sobered to see such a big question arise in my own home county, especially after having believed for over five years that there was no question.
Aaron's Review of NGS Datasheets:

Palomar Mountain:  The summit benchmark is PID  DX5064.  This establishes an NAVD88 (newer) elevation of 6,142'.  The NGVD29 elevation of 6,140' is unchanged.  Since we use the superceded NGVD29 data to compute of prominence, Edward's prominence value of 2,856' should stand.

Cuyamaca Peak:  The summit benchmark is PID DC1974.  The NAVD88 elevation is 6,508', and the NGVD elevation is 6,506'.  This is six feet lower than the elevation provided on the USGS maps.  Although there are extensive footnotes on the benchmark tearsheet, no indication is given that the benchmark is not on the highest point of land.  The summit is heavily disturbed, and it is possible that the 6,512' elevation precedes the building of the fire lookout.  As a result, the prominence has been downgraded to 2,849'. 

Whale Peak:  The summit benchmark is DX4921:  The NAVD88 elevation is 5,350' and the NGVD29 elevation is 5,348'.  This is only trivially different than the 5,349' elevation on the USGS map.