Fig. 1a. The 1913 topo map.

Borrego Desert: Historical Confusion about Blair Valley, Pinyon Mountain and Whale Peak

Fig. 1b. The 1959 topo map.


Prior to 1942, the name Pinyon Mountain was apparently applied to the Vallecito Mountains whose high point is Whale Peak, instead of to the mountain range north of the Vallecito Mountains that is now known as the Pinyon Mountains. Little Blair Valley had not been even recognized to exist. Knowing about these historical changes is important to interpret older voucher locations correctly.


You would think place names would not change with time, but we learned in 2013 that some place names in the desert portion of San Diego County have changed enough so that vouchers taken from those localities 80 years ago no longer correspond to what we call those localities today.

In November 2013, when Tom saw a paper copy of the 1942 topographic map at the new San Diego City Library, he could hardly believe his eyes. Hellhole Canyon was called "Tubb Canyon" back in 1942! "Dry Canyon" wasn't named on the 1942 map; the present day Culp Canyon was called "Tubb Canyon", and the present day Tubb Canyon wasn't given any name on the 1942 map.

This simply astounded us. How could these names get transferred between places, and when did the name changes occur?

For botanists, this means that there is a significant amount of historical time in which it is absolutely unclear where a voucher from, for example, Culp Canyon, was actually taken, since the locality depends on what source a collector was using for the name.

James then learned from using, that the historical topo in the time between 1885 and 1915 showed the present-day Salvador Canyon, which drains into Collins Valley, as "Thousand Palms Canyon". Elder Canyon from that map is now spelled as Alder Canyon.

We never dreamed that Blair Valley, Pinyon Mountain and Whale Peak had undergone similar changes, but they have.

Historical Names for Blair Valley, Pinyon Mountain and Whale Peak

We deduced the historical changes in the names for Blair Valley, Pinyon Mountain and Whale Peak as part of summarizing the locations of Calliandra eriophylla for our webpage on that species. This section details how we discovered these changes.

One location for Calliandra eriophylla came from vouchers taken in 1936, the Youngberg voucher of Calliandra eriophylla taken from southwest slope of Pinyon Mountain, along with the Gander voucher of it taken the next day, and the 1936 Gander voucher of Thymophylla pentachaeta. Another location for that species came from Larry Hendrickson and Franz Boshiero on 23 April 2005 from Smuggler Canyon.

As Tom was plotting the possible area in which the 1936 vouchers were taken, it struck him that apparent inconsistencies in the locality of those vouchers might imply that the 1936 locality was the same as the 2005 locality, even though the present-day Pinyon Mountain is nowhere near Smuggler Canyon. The localities refer to distinct geographic areas on the topo map today, a minimum of one mountain range and 2.2 miles apart; see the current topo map in Fig. 2.

After Tom mentioned this to James, James recalled the 1931 Wieslander Vegetation Map, done on top of a topo map done in 1913. This would be the latest map available to Youngberg and Gander for mapping their field localities.

Analysis of that map showed that the base 1913 topo map is largely fictional in areas that could not be seen from the existing roads at the time. The contours in Blair Valley and east, west and south of Whale Peak were made up, and do not correspond at all to the actual topography. For example:

Fig. 2 shows the 1913 topo map along with the present-day one.

Fig. 2. Top: the 1931 Wieslander Vegetation Map, done on top of the 1913 topo map. Bottom: the present-day topo map. Both maps have the 3000 foot contour highlighted in red, and the 3500 foot contour highlighted in black, with the 4879 foot peak marked with a star symbol. The maps are roughly at the same scale, but the mislocation of features on the 1913 map makes it hard to put the maps exactly on top of each other and flip back and forth. The blue cross in Smuggler Canyon on the bottom map is the Hendrickson and Boshiero Calliandra location. See text for changes between the maps.
Click on the maps for larger versions of each.

The 1913 surveyers were hugely handicapped by not having an aerial photograph of the area, and there were no roads that went into that area. They were able to survey the highest point of Whale Peak, and got its elevation correct, but were not able to see Little Blair Valley or the Pinyon Mountain Road Valley from the road that corresponds to today's S2. So they had to guess what the topography actually was, and made the minimal assumption that there was not additional ruggedness over the canyons and peaks they could see. This was the best assumption they could make, and we certainly do not fault the map-maker one bit; we would have done the map the same way.

The 1931 Wieslander survey had the same difficulty. They could see the pinyons in the vicinity of the present-day Pinyon Mountain, and marked them on the map (the gray area at top middle), but could not see that the pinyons extended to Whale Peak. They had the same difficulty with the Junipers, which extend over a much larger area than they mapped.

James then found an extremely important clue while searching for more information about the Youngberg voucher. It was written up in Madrono as a significant find!

While on a field trip in the vicinity of Pinyon (Vallecito) Mountain in eastern San Diego County, January 1-3, 1936, a group from the Department of Biology of San Diego State College noted the occurrence of Calliandra eriophylla Benth., a plant which previously has been recorded from only one locality in California: near Ogilby, eastern Imperial County. The colony, discovered by Miss Florence Youngberg as the party was descending Pinyon Mountain, is on the south side of the mountain, about one-half mile from the camp at the cave in Upper Blair Valley.
Madrono 1936 3:254.

That nailed it! Their Upper Blair Valley is what we now call Little Blair Valley. The highest point of Little Blair Valley is the beginning of the Pictograph trail. The cave at the beginning of the Pictograph Trail is well-known, and there is a second cave near the Pictographs. The Pictograph boulder on the trail is almost exactly one-half mile from the Smuggler Canyon Hendrickson and Boshiero Calliandra location.

After the discovery of the Calliandra by Youngberg on 2 January 1936, the group went back the next day to take eight more vouchers of the Calliandra. Two other species were vouchered on 3 January 1936 at the same location, the "base of Pinyon Mountain": Pellaea mucronata and Sarcostemma cynanchoides. We saw both of those species at the Smuggler Canyon Calliandra location in our field survey on 15 December 2013.

In addition, on our field survey in Smuggler Canyon on 15 December 2013, we saw every one of species in the 2 January 1936 vouchers up to Gander's #369. His voucher #370 is Thymophylla, and #371 is Pinus monophylla. Since the pine occurs at significantly higher elevation, they must have explored elevations above the Calliandra location.

Gander's vouchers #328 to #345 all have the locality of Upper Blair Valley, and we recorded every one of those species at the beginning of the Pictograph Trail, including the uncommon Senna covesii, Gander #345.

His next vouchers were taken in the Wash at south end of Pinyon Mountain, including a voucher of Justicia californica. We surveyed down to the top of the waterfall in Smuggler Canyon that gives a great view of the Vallecito Valley, and were surprised to find a population of Justicia californica there, since we had never seen it in five previous surveys of the Pinyon Mountain Road area. This species occurs nowhere else that we know of in this area. We have surveyed the south side of what is known now as Pinyon Mountain twice, and the two routes from Pinyon Mountain Road to Whale Peak three times, and have not seen Justicia californica nor Calliandra there. Nor are there any other vouchers of Justicia from the Pinyon Mountain Road area, except for the voucher discussed here.

This is the highest-elevation population of Justicia californica that we have found in 43 of our surveys that we have digitized in the entire Borrego Desert area, which ranged from 800 to 4000 feet elevation. This population is at 3060 feet elevation. The next-highest elevation population we have found is at 2600 feet in the Upper Tubb Canyon / Big Spring area. This waterfall / overlook is on a direct south-facing slope, amidst a landscape composed almost entirely of exposed rocks. This is probably one of the the hottest and driest localities in this area, with good air drainage, allowing a lower-elevation desert species to reach its highest elevation here.

Finally, the map giving San Diego County voucher locations in Higgins 1949 Ferns and Flowering Plants of San Diego County shows clearly that the mountain range which has Whale Peak as its high point was the Pinyon Mountain of the vouchers. That map shows only a single mountain range to the east of Blair Valley, labeled Pinyon Mountains. It also shows only Blair Valley, and does not give a location of Little Blair Valley.

This discovery of the true locations for the 75 vouchers taken from this area on 2 and 3 January 1936 now allows those to be given much more accurate georeferenced locations than was previously possible.

We thank Bill Sullivan and Kate Harper for comments on this page.

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Copyright © 2013 by Tom Chester and James Dillane.
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Updated 29 December 2013.