Plant Guide to Ernie Maxwell Scenic Trail, San Jacinto Mountains

Introduction and Explanation of Plant Trail Guides

Highlights of This Trail
Fieldwork Dates and Summary of List Changes With Time
The Plant Guide
Comments On Specific Species


The Ernie Maxwell Scenic Trail is a beautiful and very popular trail from the bottom of Humber Park in Idyllwild to a rather unglorious end at the dusty non-scenic dirt road of Tahquitz View Drive just north of the turnoff to the South Ridge Trailhead.

The trail itself is indeed scenic, primarily for the views of the plants and rocks along the trail, but it also has a few views to the west that extend to the ocean. One might expect to see lots of views of the nearby homes all along the trail, but that doesn't happen; one feels surrounded by forest all the time. Most of the human traces along the way are large numbers of piles of twigs, branches, and cut-up dead trees stacked for burning in the wet season.

The trail is completely shaded for perhaps 80% or so of its length, with scattered regular shade in the remaining 20% of the trail. The openings in the forest have their own suite of delightful species; many of these areas must be absolutely beautiful with bloom in years when it rains.

The trail traverses a number of delightful drainages, but there is a bittersweet tinge to many of them that are probably only shadows of what they once were. Nearly every moist side drainage has a pipe carrying the precious water away from the plants and animals.

New species are encountered regularly along the trail, despite the trail staying in a fairly narrow range of elevation, and staying mostly with the same west-facing slope. This is very different from a similar trail at higher elevation, such as the PCT from Devils Slide to the South Ridge Trail, which is very depauperate in the total number of species. This difference is probably mainly due to the elevation, with the sunnier more open spots here having some chaparral species, whereas at higher elevation there is no chance of those chaparral species sneaking in there.

Many of the species found here are those also seen on the lower South Ridge Trail, which makes sense since the lower part of the two trails are only ~0.4 miles and ~900 feet of elevation apart. It is in fact quite interesting to be hiking directly below and almost parallel to that trail.

No permit is required to hike this trail, since it does not enter the San Jacinto Wilderness. An Adventure Pass is required to park within Humber Park, but parking spaces just outside Humber Park are about the same distance away from the upper trailhead, and do not require a Pass.

The trail is 2.3 miles one way, 4.6 miles round-trip, with ~750 feet of elevation gain and loss for the round-trip. (I computed 720 feet of gain and loss from all stretches with noticeable change in elevation, and rounded it up to 750 feet to include the imperceptible ups and downs on the trail.) The trail is nearly flat for the first 0.65 miles below Humber Park with an elevation change of only 100 feet, a rate of just 150 feet per mile. The trail then descends 220 feet to mile 1.06 at the rate of about 500 feet per mile. The trail is then again nearly flat to mile 1.5. The last 0.9 miles of the trail descends 380 feet at the rate of 430 feet per mile.

If you would like a shorter less-strenuous trip, hiking to mile 1.52 and back is 3.0 miles roundtrip, with just 350 feet of elevation gain and loss, and you'll only miss one of the on-trail (numbered) species on the trail, and six of the off-trail species.

Note that the two most popular guidebooks incorrectly state the elevation gain of this trail, which is hard to understand since the trail is clearly shown on the USGS topographic map. Robinson and Harris (2006) give 300 feet as the total gain for the one-way trip from the bottom to the top; the actual gain is a minimum of 700 feet.

Ferranti and Koenig (2000) apparently never give the actual elevation gain and loss along a trail in their guidebook, only the elevation difference between the bottom and top. This is a very unusual and misleading way to report it, especially since they call it the elevation gain. (I.e., if they reported their version of elevation gain for a hike from the North Rim of the Grand Canyon down to the bottom and then up the South Rim, they would report an elevation gain of zero feet, despite there being a true elevation gain of nearly one mile along that route!) They only give 300 feet for the elevation difference between the bottom and top; the actual difference is 6400 - 5720 = 680 feet.

For photographs of some of the plants in bloom on 22 May 2009, see Pictures From Ernie Maxwell Scenic Trail, San Jacinto Mountains, 22 May 2009.

Highlights of This Trail

This section not updated since 2009.

The botanical highlights of this trail are:

Number of Unique Taxa On This Trail

The following histogram gives the number of trails in our database that contain each taxon on this trail (not including the taxa seen only off-trail given at the end of the guide). We had 147 trails in our database when this histogram was made; 11 of those trails, including this one, are in the west side or south side of San Jacinto Mountain, with an additional 12 trails at higher elevation at San Jacinto Mountains. A number of "1" means the taxon has only been found on this trail among the trails in our database; numbers of "11" or smaller may indicate taxa found only in this area of San Jacinto Mountain.

Number of Trails
Containing A Taxon
Number Of Taxa
On This Trail
% of Taxa
On This Trail
Total Taxa94100%

We found 5 additional species not in the above table, since they have not been identified yet. The unidentified ones are marked with ? or sp in the id? column in the guide, and have no entry in the #all column.

Fieldwork Dates and Summary of List Changes With Time

This section not updated since 2009.

The following table gives the dates the trail was walked and taxa recorded. After each visit, the table gives the total number of taxa on the list and the breakdown of the taxa without positive identification. See Explanation of Plant Trail Guides to understand the symbols below.

Visit DateVisit ## taxa# "?"# "sp"# "~"# "ssp"

The Plant Guide

See Plant Checklist For Ernie Maxwell Scenic Trail for a list of the species in the guide below in traditional family order.

For photographs of some of the plants in bloom on 22 May 2009, see Pictures From Ernie Maxwell Scenic Trail, San Jacinto Mountains, 22 May 2009.

The mileages in the guide come from Topo! and a GPS recording of the trail made on 29 May 2015, and should be differentially accurate to ~0.01-0.02 miles. The total mileage of the trail is probably a bit longer than the 2.29 miles given in the guide, but is probably less than the 2.35 miles from the GPS track, which includes GPS jitter between each point.

This guide is still in the 1993 First Edition Jepson Manual system.

See Explanation of Plant Trail Guides for an explanation of the column headers.

Version for printing, without lines and other text on this page: html (5 pages) or pdf Clickbook booklet (1 double-sided page). (See printing instructions for an explanation of these options)

MileS#id?Common NameLatin Name#here
0.00rBeginning of trail at Ernie Maxwell sign; 6400 feet (1951 m) elevation.
0.00l(incense-cedar mistletoe, Phoradendron libocedri)
0.00r1incense-cedarCalocedrus decurrens99 / 9
0.00r2ponderosa pinePinus ponderosa50 / 9
0.00r(snow-plant, Sarcodes sanguinea)
0.00b3California black oakQuercus kelloggii99 / 9
0.00r(Sierra Nevada lotus, Lotus nevadensis var. nevadensis)
0.01lJct. shortcut use trail from south end of parking area
0.01r4canyon live oakQuercus chrysolepis99 / 9
0.01l(white fir, Abies concolor)
0.02r(bristly bird's beak, Cordylanthus rigidus ssp. setigerus)
0.02r5Sierra Nevada lotusLotus nevadensis var. nevadensis40 / 9
0.02rJct. use trail to road
0.02r(broad-leaved lotus, Lotus crassifolius var. crassifolius)
0.02b6white firAbies concolor30 / 9
0.02r7fir mistletoePhoradendron pauciflorum1 / 1
0.03r(sugar pine, Pinus lambertiana)
0.06lJct. another shortcut use trail from south end of parking area
0.08r8western azaleaRhododendron occidentale40 / 2
0.08l(pinedrops, Pterospora andromedea)
0.09r9mountain pink currantRibes nevadense50 / 5
0.09b(thimbleberry, Rubus parviflorus)
0.09b10white alderAlnus rhombifolia3 / 2
0.09Cross moist creek, the drainage from most of the area south of Saddle Junction and north of Lily Rock / Tahquitz Peak
0.09r11thimbleberryRubus parviflorus20 / 2
0.09l12sugar pinePinus lambertiana40 / 9
0.10r(bracken, Pteridium aquilinum var. pubescens)
0.11r13pinedropsPterospora andromedea4 / 1
0.13Trail turns left 90°
0.14b14Grinnell's beardtonguePenstemon grinnellii var. grinnellii10 / 2
0.14l(mountain whitethorn, Ceanothus cordulatus)
0.15r(common bedstraw, Galium aparine)
0.15r15mountain whitethornCeanothus cordulatusdead2 / 2
0.18lJct. “Climber's Trail” to Lily Rock
0.18r(*downy brome, Bromus tectorum)
0.18l16forest sedgeCarex multicaulis20 / 9
0.18l17green miner's lettuceClaytonia parviflora ssp. viridis99 / 2
0.18r18Jones' prickly-nut cryptanthaCryptantha muricata var. jonesii20 / 9
0.19b19common bedstrawGalium aparine5 / 3
0.19b20Laguna Mtns. jewel-flowerStreptanthus bernardinus30 / 2
0.19l21beautiful hulseaHulsea vestita ssp. callicarpha5 / 2
0.19l(western wallflower, Erysimum capitatum ssp. capitatum)
0.24l22Coulter pinePinus coulteri30 / 9
0.24lJct. use trail
0.27l23mountain rock-cressArabis holboellii+20 / 5
0.28l24June grassKoeleria macranthadead99 / 9
0.29lJct. use trail
0.29r(pink-bracted manzanita, Arctostaphylos pringlei ssp. drupacea)
0.29b25San Jacinto buckwheatEriogonum apiculatum50 / 2
0.29b26naked buckwheatEriogonum nudum var. pauciflorum50 / 9
0.29b27squirreltailElymus elymoides50 / 9
0.29l28bristly bird's beakCordylanthus rigidus ssp. setigerus99 / 9
0.29l29spgroundsmokeGayophytum sp.4 / 2
0.29l30mountain red-root cryptanthaCryptantha micrantha var. lepida20 / 5
0.29l31splendid giliaGilia splendens ssp. splendens3 / 1
0.29l32plain mariposa lilyCalochortus invenustus99 / 9
0.30r33Fremont's goosefootChenopodium fremontii2 / 1
0.33Cross very small drainage
0.3334spotted coralrootCorallorhiza maculata15 / 3
0.35Cross very small drainage
0.36b35pink-bracted manzanitaArctostaphylos pringlei ssp. drupacea50 / 9
0.36l36oak mistletoePhoradendron villosum30 / 3
0.36l(southern mountain woolly-star, Eriastrum densifolium ssp. austromontanum)
0.36r37short-flowered monardellaMonardella nana ssp. tenuiflora50 / 9
0.36r?(plant with two leaves that are 2 ternate like sweet-cicely, Osmorhiza sp.)
0.36l38wild sweetpeaLathyrus vestitus var. vestitus99 / 9
0.36l39western wallflowerErysimum capitatum ssp. capitatum20 / 3
0.36b40Wright's buckwheatEriogonum wrightii var. membranaceum40 / 9
0.36l41California-asterLessingia filaginifolia var. filaginifolia40 / 9
0.37b42mountain grape-soda lupineLupinus excubitus var. austromontanus30 / 9
0.37r43Parish's tauschiaTauschia parishiidead30 / 9
0.38b44white catch-flySilene verecunda ssp. platyota40 / 9
0.38r45mountain mugwortArtemisia ludoviciana ssp. incompta10 / 1
0.38r(golden yarrow, Eriophyllum confertiflorum var. confertiflorum)
0.41l46Hall's bromeBromus orcuttianus var. hallii10 / 3
0.41l47leafy daisyErigeron foliosus var. foliosus20 / 9
0.41r48American vetchVicia americana var. americana20 / 5
0.42l49goldenrodSolidago californica40 / 5
0.42l50white hawkweedHieracium albiflorum10 / 2
0.44l51golden yarrowEriophyllum confertiflorum var. confertiflorum99 / 9
0.44l52Martin's paintbrushCastilleja applegatei ssp. martinii30 / 9
0.45l53slender everlastingGnaphalium canescens ssp. thermaledead3 / 3
0.47l54strigose lotusLotus strigosus30 / 4
0.49Cross small drainage
0.49l55narrowleaf bedstrawGalium angustifolium ssp. angustifolium30 / 9
0.50l56bajada lupineLupinus concinnus ssp. optatus10 / 3
0.50l57southern mountain woolly-starEriastrum densifolium ssp. austromontanum30 / 5
0.50r58snow-plantSarcodes sanguinea1 / 1
0.52l59mountain California-fuchsiaEpilobium canum ssp. latifoliumdead40 / 5
0.60Cross dry drainage from southwest side of Lily Rock
0.65Trail begins to descend more steeply; elevation ~6300 feet (1920 m)
0.67l60Yosemite rockcressArabis repanda var. repandadead30 / 5
0.67rJct. trail probably leading to road just below; stay left
0.71Enter forest of oak mistletoe, Phoradendron villosum, for 0.01 miles
0.72l(San Bernardino rubber rabbitbrush, Chrysothamnus nauseosus ssp. bernardinus)
0.73Leave dense continuous forest; forest now interspersed with sunny open areas
0.77b61interior live oakQuercus wislizeni var. frutescens30 / 5
0.79l62*downy bromeBromus tectorum99 / 9
0.80l(oracle oak, Quercus Xmorehus)
0.82b63small fescueVulpia microstachys20 / 3
0.82l64pine dwarf-mistletoeArceuthobium campylopodum1 / 1
0.82l65white-margined oxythecaOxytheca emarginata10 / 2
0.83l(southern honeysuckle, Lonicera subspicata var. denudata)
0.84b66California elegant rock-cressArabis sparsiflora var. californica20 / 5
0.84r67southern honeysuckleLonicera subspicata var. denudata2 / 2
0.85l68whisker-brushLinanthus ciliatus99 / 9
The following two species were found farther along the trail, but without a precise location
?69hybrid manzanitaArctostaphylos patula X A. pringlei ssp. drupacea1 / 1
?70sticky lessingiaLessingia glandulifera var. glandulifera1 / 1
0.87l(California cliff-brake, Pellaea mucronata var. californica)
0.91l71Davidson's buckwheatEriogonum davidsonii80 / 1
0.92Cross drainage
0.92l72broad-leaved lotusLotus crassifolius var. crassifolius10 / 2
0.93l73little prince's pineChimaphila menziesii10 / 2
0.97Switchback left at ridge; elevation ~6100 feet (1859 m)
0.99Cross moist drainage from Tahquitz Peak
0.99l(western columbine, Aquilegia formosadead )
1.03b74spreading dogbaneApocynum androsaemifolium99 / 2
1.06Trail levels off; elevation ~6080 feet (1853 m)
1.15r75pine cryptanthaCryptantha simulans50 / 9
1.18l76blue dicksDichelostemma capitatum ssp. capitatum20 / 4
1.18Cross dry drainage
1.18l77volcanic giliaGilia ochroleuca ssp. exilis99 / 9
1.18l78annual phloxPhlox gracilis30 / 4
1.18l79diamond-petaled clarkiaClarkia rhomboidea99 / 9
1.20l80southern miner's lettuceClaytonia perfoliata ssp. mexicana99 / 5
1.21r(SAX woodland star, Lithophragma affine)
1.21r81California thistleCirsium occidentale var. californicum3 / 1
1.2282oracle oakQuercus Xmorehus1 / 1
1.22lfield of plain mariposa lily, Calochortus invenustus
1.22l83spear-leaved mountain dandelionAgoseris retrorsa50 / 9
1.22b84*garden trumpet daffodilNarcissus hybrid99 / 1
1.23r(Large water tank)
1.23l85incense-cedar mistletoePhoradendron libocedri1 / 1
1.23r86imbricate phaceliaPhacelia imbricata ssp. patula75 / 1
1.31b87brackenPteridium aquilinum var. pubescens2 / 1
1.31Cross moist drainage coming from base of upper switchbacks on South Ridge Trail; minor local low point; elevation ~6080 feet (1853 m)
1.31b(Parish's burning bush, Euonymus occidentalis var. parishii; sticky cinquefoil, Potentilla glandulosa ssp. reflexa)
1.31l88Parish's lupineLupinus latifolius var. parishii5 / 3
1.31r89western columbineAquilegia formosa1 / 1
1.31r(California wild rose, Rosa californica)
1.35r90musk monkeyflowerMimulus moschatus20 / 1
1.35l(Durango root, Datisca glomerata in distance)
1.35b91sticky cinquefoilPotentilla glandulosa ssp. reflexa20 / 4
1.35Cross moist drainage coming from small saddle / level section of South Ridge Trail at 7600 feet elevation on that trail. The following two species are found upstream off trail either at this drainage or a nearby one: lemon lily, Lilium parryi; subarctic lady-fern, Athyrium filix-femina var. cyclosorum
1.35r92~common monkeyflowerMimulus guttatus1 / 1
1.35r93floriferous monkeyflowerMimulus floribundus20 / 1
1.35r(fragile sheath sedge, Carex fracta)
1.3994woodland starLithophragma affine75 / 5
1.41r(blue larkspur, Delphinium parryi ssp. parryi)
1.42Minor local high point; elevation ~6100 feet (1859 m)
1.42r95clustered broom-rapeOrobanche fasciculatadead1 / 1
1.46l96Parish' Jacumba milk-vetchAstragalus douglasii var. parishii10 / 4
1.46l97scattered blazing starMentzelia dispersa10 / 1
1.48l98*prickly sow thistleSonchus asper ssp. asper1 / 1
1.50Cross small dry drainage; elevation 6000 feet (1829 m)
1.62l99birch-leaf mountain-mahoganyCercocarpus betuloides var. betuloides1 / 1
1.66rJct. steep path down to road below with deep roadcut
1.66l(rock goldenbush, Ericameria cuneata var. cuneata in distance)
1.67l100rock goldenbushEricameria cuneata var. cuneata1 / 1
1.73Cross drainage
1.73l(Scouler's willow, Salix scouleriana)
1.82l101goldenstarBloomeria crocea10 / 2
1.88l(mountain piperia, Piperia transversa)
1.89l102California chicoryRafinesquia californica1 / 1
1.91l103mountain piperiaPiperia transversa3 / 2
1.94l104fragile sheath sedgeCarex fracta2 / 2
1.94r105California wild roseRosa californica1 / 1
1.94Cross moist drainage; elevation 5800 feet (1768 m)
2.00l(way off-trail: Mexican manzanita, Arctostaphylos pungens)
2.07l106southern Chinese housesCollinsia concolor50 / 1
2.10r(stream orchid, Epipactis gigantea, at seep halfway down to Tahquitz View Drive, the road below the trail)
2.11r107curve-flowered skullcapScutellaria siphocampyloides30 / 1
2.17Cross dry drainage below spring just north of South Ridge Spring
2.17r(*garden pyracantha, Pyracantha coccinea; Durango root, Datisca glomerata)
2.29End trail at Tahquitz View Drive just north of the turnoff to the South Ridge Trailhead; elevation 5720 feet (1743 m); return the way you came

Comments On Specific Species

Arabis holboellii. Unfortunately, this isn't the appropriate name for these plants, but there is no binomial name currently available for these plants. See Recent Changes in Delineation of These Species for more information.

Dead. The first plant seen of each of these species in 2007 through 2009 was dead in 2015. The first live plant of those species in 2015 is not noted in the guide. All the species are found later on the trail except for the Orobanche fasciculata, which was previously found as only a single plant.

We thank Nancy Accola, Adrienne Ballwey, Kate Harper, Jim Roberts, Elize Van Zandt, and Bruce Watts for help with the 29 May 2015 survey. Adrienne found the only plants of California cliff-brake, Pellaea mucronata var. californica, and Bruce found the only oracle oak on trail.

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Copyright © 2007-2015 by Tom Chester and Dave Stith.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
Comments and feedback: Tom Chester
Updated 1 June 2015.