The Flora of the PCT
A9 Highway 78 to Highway S22 (Barrel Springs)

Fig. 1.
Top row. Left: Ocotillo in front of Scissors Crossing, where San Felipe Creek crosses SR78, with Granite Mountain in the background. Right: lace-fringed spineflower, Chorizanthe fimbriata var. laciniata.

Middle row. Left: Desert community members at beginning of this segment: Mohave yucca, Yucca schidigera; Gander's cholla, Cylindropuntia ganderi; ocotillo, Fouquieria splendens; California juniper, Juniperus californica. Right: Typical segment of trail contouring around each and every side canyon, showing post-burn shrubs. Shaun Hawke is gazing at Granite Mountain in the background, probably remembering the times she's hiked and botanized the PCT there in the past. The PCT to the south contours around the west side (right side of photograph) of Granite Mountain.

Bottom row. Left: California barrel cactus, Ferocactus cylindraceus. Right: closeup of lace-fringed spineflower, Chorizanthe fimbriata var. laciniata.

Photos by RT Hawke taken on this segment of the PCT on 18 April 2014. Click on the pictures for larger versions.

SegmentSegment StartSegment EndSegment LengthElevation (feet)
MinMaxRange
A9Highway 78Highway 2224.0 miles225044202170
Subsegments
   A9aHighway 784.2 miles from Highway 784.2 miles22503080830
   A9abHighway 78High Point on PCT18.5 miles225044202170
   A9cHighway S22High Point on PCT5.5 miles34504420970
This section covers roughly mile 78 to mile 102 from the Mexican Border (see notes on accuracy of mileages).
Topo! gives 22.9 miles for this segment. The PCT Data Book gives 23.9 miles. We've adopted 24.0 miles.
The one-way hike from south to north has a total elevation gain of 2970 feet, and a total elevation loss of 1770 feet see the profile below.
The one-way hike from north to south has a total elevation gain of 1770 feet, and a total elevation loss of 2970 feet.
A round-trip hike of this section is 48.0 miles, with an elevation gain and loss of 4740 feet.

We have broken up this section into three units. Section A9a is the first 4.2 miles of trail. Section A9b is the middle part of the trail, but since the easiest way to access this is from either end of the trail, we have included it with Section A9a as Section A9ab, which covers the first 18.5 miles of trail. Section A9c is the last 5.5 miles of trail, which we have done from Highway S22 south to the high point of the trail.

Introduction
Survey Dates
The Plant Checklists

Introduction

This is a very long, dry section of trail, 24 miles from Highway 78 just east of Scissors Crossing to Highway S22 just past Barrel Springs.

But this is a fascinating segment botanically! This is the only part of the PCT that passes through an area with the classic signature plants of the Lower Colorado Desert vegetation, with species as ocotillo, Fouquieria splendens; California barrel cactus, Ferocactus cylindraceus; and teddy-bear cholla, Opuntia bigelovii (Figs. 1 and 2). In fact, this is one of the best places to observe California barrel cactus, accompanied here by Gander's cholla, Cylindropuntia ganderi; Engelmann's hedgehog cactus, Echinocereus engelmannii; and California fish-hook cactus, Mammillaria dioica.

Fig. 2. A dense stand of California barrel cactus, Ferocactus cylindraceus; accompanied by Gander's cholla, Cylindropuntia ganderi; desert agave, Agave deserti; and teddy-bear cholla, Opuntia bigelovii. This is the only section of the PCT with signature plants of the Lower Colorado Desert vegetation.
Photo by Tom Chester, taken on 6 January 2012 from the PCT just above Scissors Crossing.
Click on the picture for a full camera frame taken just to the left of this photograph, looking down to Scissors Crossing.

You may wonder how it is that the Pacific Crest Trail is passing through a low-elevation desert area. There are two reasons. First, the trail really should be located 10 miles to the west, following the crest of the Volcan Mountains, as mandated by the original Congressional authorization for the PCT. However, it was difficult to gain access to that area, which is mostly private property, so the Forest Service located the trail in mostly-public lands here.

Second, the area around Scissors Crossing, at the beginning of the segment, is the very westernmost extension of the Lower Colorado Desert vegetation here, thanks to the rain shadow of the Laguna Mountains, the low elevations around Scissors Crossing, and the south-facing slopes here.

Although the PCT crosses the Lower Colorado Desert again at Banning Pass, most of the signature plants of that desert are missing at that location.

The trail begins in open Borrego Desert vegetation, and gradually transitions to desert chaparral for most of its length. Just before the high point on the trail, chamise chaparral appears, which becomes dense past the high point (Fig. 3). The vegetation at the beginning and end of this segment is completely different (compare Figs. 2 and 3).

Fig. 3. Dense stand of chamise, Adenostoma fasciculatum, with only a few other species here and there.
Photo by Tom Chester, taken on 10 January 2015 from the PCT just north of the high point of this section, looking southwest.
Click on the picture for a larger version.

The first 1.5 miles of this segment climbs the slopes of the San Felipe Hills to reach an elevation of 3000 feet elevation. It then stays on the southwest slopes of the San Felipe Hills, between elevations of 3000 and 3600 feet, for the next 12 miles. Although on average the trail parallels the nearly-straight line Highway S2, northward progress on the trail is slow, since the trail weaves in and out of numerous side canyons along the way in order to stay nearly at a constant elevation for long stretches.

Near mile 13, the trail gets serious about gaining elevation, and crosses the ridgeline of the San Felipe Hills at mile 18.5. The trail then descends to Highway S22 on the northeast side of the ridgeline.

This area has experienced a number of fires in recent years. This is probably due to an introduced species, cheat grass, Bromus tectorum, that fills the spaces between shrubs and catches on fire easily when dried up, enabling fire to sweep through areas that normally would not burn so readily.

 

Fig. 4. Left: Trail Map for the PCT Section A9 from Highway 78 to Highway S22, from USDA Forest Service Interactive Map.
Right: Elevation profile from Highway 78 to Highway S22, from south to north.
Click on the pictures for larger versions.

Survey Dates

The surveys of this section of trail, in time order, are:

The Plant Checklists

There are usually four different versions of the Plant Checklists, which differ depending on:

We have broken up this section into three units. Section A9a is the first 4.2 miles of trail. Section A9b is the middle part of the trail, but since the easiest way to access this is from either end of the trail, we have included it with Section A9a as Section A9ab, which covers the first 18.5 miles of trail. Section A9c is the last 5.5 miles of trail, which we have done from Highway S22 south to the high point of the trail.

Because there are only 16 species found in Section A9b that are not found in Section A9a, we give only the lists for Section A9ab. The additional 16 species are numbered 181 to 222 in the trail order list, and so are easily identified there and ignored if one wants a list only for Section A9a. The family order list retains the number from the trail order list, so those species again can easily be ignored if one wants only the A9a family order flora.

The entire Section A9

Only Section A9a and Section A9ab

Only Section A9c

Separate condensed print versions of just the checklist names are available for all except for the Calflora thumbnail picture version, as a link on each of those pages.


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Copyright © 2015 by RT Hawke, Shaun Hawke, Tom Chester, Adrienne Ballwey, Kate Harper, Mike Crouse, James Dillane, Keir Morse, Jim Roberts, and Nancy Accola
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
http://tchester.org/pct/a/a9_SR78_S22.html
Comments and feedback: Tom Chester
Updated 2 December 2015.