Arizonensis --> Sonoran Desert Naturalist --> Sonoran Desert Places --> Usery Mountain

Usery Mountain Park
Mesa, Arizona


This Maricopa County Park, located northeast of Mesa preserves a fine example of Upper Sonoran Desert and provides many recreational opportunities for both visitors and residents. Drive north on Ellsworth Road from US-60. Ellsworth becomes Usery Pass Road then the park entrance is on the east side of the road north of McKelleps.

There is a campground and a horse staging area in addition to 20 trails. The park sets at the western end of the Goldfield Mountains and is adjacent to extensive Forest Service land. The most popular trail, The Wind Cave Trail, is located on national forest land. In the spring time parking spaces become limiting, so it is best to arrive early for a hike.

The Geology is primarily volcanic. The lower slopes and flats of Pass Mountain are alluvium from adjacent volcanic rocks. The base of Pass Mountain is ancient weathered granite and then there is a cap of yellow and brown volcanic tuff/rhyolite. The wind cave is formed at the boundary between the tuff and granite. Water seeping from the roof of the cave supports hanging gardens of Four O'clocks and Rock Daisy.

The species lists given here are for the Wind Cave trail and Pass Mountain.

View Larger Map. Directions: From the intersection of McKellips Rd. and Ellsworth Rd. in Mesa, drive about 1¼ miles north on Usery Pass Rd. to park entrance on right.

Field Trip Report:
April 16, 2006

Wind Cave trail ascends the west side of Pass Mountain to a small cave sculpted out of the side of the mountain. The trail is about 2-1/2 km in length with moderately steep sections and with plenty of loose gravel. Most of the trail is on a well formed bajada (accumulated alluvium at the base of a mountain slope) where vegetation is characteristically lush. Note that creosote bush is common on the desert flats nearby, is absent from the bajada, then reappears above the bajada on the rocky slopes where soils are thin.

Just a month ago the Sonoran Desert was all brown and gray after 5 months without rain. Even the cacti were shriveling and yellowed. The heavy rains over the weekend of March 11 changed that and now the desert is again green and vibrant. Ocotillos have leafed and sport fists of lipstick-red flowers at their branch tips. Triangle-leaf bursage has produced an abundance of pollen-shedding flowers. Also showily in bloom were Desert Senna, Chuparosa and Fairy Duster. Near the cave I found a Ragged Rock Flower (Crossoma bigelovii} shrub in full bloom. Normally this plant blooms in early January, but like most desert plants it can adjust blooming and fruiting times to match unseasonable weather. Altogether I counted 23 plant species in bloom including the first of the hedgehog cactus, janusia vine, jojoba, desert lavender, sweet bush and littleseed mully. Annuals are few and very small.

The Buckhorn Chollas are growing lots new shoots with succulent leaves (fleshy, ca. 2 cm long, clustered at growing tips) that can be carefully twisted off and eaten raw for a tasty snack. Eventually the leaves just shrivel and are shed so nibble all you like! Two kinds of butterflies were seen: Pygmy Blue and Sara's Orange Tip.

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In general order of Abundance:

  1. Rock Wren --S,F,W,Sp -- Common little birds which frequently give spirited high pitched trills while perched on top of a boulder or summit. Their drab gray and brown color blends perfectly with the desert colors.
  2. Cactus Wren --S,F,W,Sp--
  3. Canyon Wren --F,W,Sp --
  4. Verdin -- Auriparus flaviceps -- S,F,W,Sp-- Tiny birds, barely larger than a hummingbird. Drab gray brown with a majestic yellow head.
  5. Costa's Hummingbird --Sp,S-- Common. Green back; throat of males purple.
  6. Black-throated Sparrow --S,F,W,Sp
  7. Black-tailed Gnatcatcher -- Polioptila melanura -- S,F,W,Sp-- Fairly common in the bigger washes where the trees grow a bit larger.
  8. Canyon Towhee -- Pipilo fuscus --F,W,Sp-- large plain brown sparrow.
  9. Gila Woodpecker -- Melanerpes uropygialis --S,F,W,Sp-- Common woodpecker that builds nest holes in the Saguaro Cactus.
  10. Ash-throated Flycatcher -- S,F,W,Sp -- spring especially, rare in winter
  11. Turkey Vulture -- Sp,S,F,-- Large conspicuous soaring birds.
  12. White-crowned Sparrow -- Zonotrichia leucophrys --F,W,Sp--
  13. Mourning Dove --S,F,W,Sp--
  14. Curve-billed Thrasher -- Toxostoma curvirostre --S,F,W,Sp--
  15. Rufous-crowned Sparrow --S,F,W,Sp-- One seen near cave

Photo copyright Michael Plagens
Canyon Towhee

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Visitors eating their lunches at the wind cave offer enough food scraps to support a small colony of Cliff Chipmunks (Eutamias dorsalis). Chipmunks are distinguished from other squirrels by the stripes on the sides of the face.

Photo copyright Michael Plagens
Cliff Chipmunk


Common Springtime Butterflies.

  1. Hackberry Butterfly (Asterocampa leilia)
  2. Painted Lady (Vanessa cardui)
  3. Pima Orange Tip (Anthocharis pima)
  4. Sara Orangetip (Anthocharis sara)
  5. Pygmy Blue -- Brephidium exile

Sara Orange Tip (Anthocharis sara)
Photos from AZ Butterflies

Western Pygmy Blue (Brephidium exile)
This is probably the World's smallest butterfly species.


In order of Abundance:
  1. Buckhorn Cholla (Opuntia acanthocarpa) -- Most of the chollas are of this species.
  2. Saguaro Cactus (Cereus giganteus) -- Distinguish small individuals by their gray spines.
  3. Compass Barrel Cactus (Ferocactus acanthodes) -- Spines tinged with red and yellow.
  4. Engelmann Hedgehog Cactus (Echinocereus engelmannii)
  5. Teddy Bear Cholla (Opuntia bigelovii) -- The joints frequently fall off and begin rooting and may grow into new plants.
  6. Pincushion Cactus (Mammilaria sp.) --
  7. Chain-fruit Cholla (Opuntia fulgida )
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Shrubs and Trees

In general order of Abundance:

  1. Triangle-leaf Bursage -- Ambrosia deltoidea -- The most common plant. Often leafless after periods of drought or hard frost.
  2. Foothills Palo Verde (Cercidium microphyllum) --
  3. Jojoba -- Simmondsia chinensis --
  4. Brittle Bush (Encelia farinosa) -
  5. Ocotillo (Fouquieria splendens) -
  6. Wolfberry (Lycium 2 spp.) -
  7. Chuparosa (Justicia californica)
  8. Sweet Bush -- Bebbia juncea - Fairly common
  9. Fairy Duster -- Calliandra eriophylla
  10. Canyon Ragweed (Ambrosia ambrosioides)
  11. Janusia (Janusia gracilis) - a twisty, viny plant
  12. Trixis -- Trixis californica --
  13. Flat-topped Buckwheat -- Eriogonum fasciculatum
  14. Mormon Tea (Ephedra aspera)
  15. Creosote Bush (Larrea tridentata)
  16. Globe Mallow (Sphaeralcea ambigua) - Bares peach colored blooms after periods of rain otherwise it is difficult to find
  17. Velvet Mesquite -- Prosopis velutina - A few in the washes
  18. Desert Lavender (Hyptis emoryi) -
  19. Ragged Rock Flower -- Crossosoma bigelovii
mature fruit of Simmondsia chinensis conaining one seed; photo © Mike Plagens

Jojoba seeds appear only on the female shrubs and mature by mid summer. They are the source of jojoba oil used in lotions and other products as a substitute for whale oil. Bitter to the taste, but edible in limited quantities.

Spring Wildflowers obs. April 2, 2000

Along trail up to Wind Cave. Ocotillo and Chuparosa with their bright red flowers were the most conspicuous blooms.

White Flowers

  1. Flat-topped Buckwheat -- Eriogonum fasciculatum
  2. Arch-nutted Comb Bur -- Pectocarya recurvata
  3. Lance-leaf Ditaxis -- Argythamnia lanceolata
  4. Wright's Buckwheat -- Eriogonum wrightii
  5. Emory Rock Daisy -- Perityle emoryi
  6. Desert Wishbone Bush -- Mirabilis laevis

Green Flowers

  1. Triangle-leaf Bursage -- Ambrosia deltoidea
  2. Canyon Ragweed -- Ambrosia ambrosioides
  3. Jojoba -- Simmondsia chinensis

Yellow Flowers

  1. Brittlebush -- Encelia farinosa
  2. Desert Marigold -- Baileya multiradiata
  3. Trixis -- Trixis californica
  4. California Sundrop -- Camissonia californica
  5. Creosote Bush -- Larrea tridentata
  6. Sweet Bush -- Bebbia juncea

Orange Flowers

  1. Desert Globe Mallow -- Sphaeralcia ambigua
  2. San Felipe Marigold -- Adenophyllum porophylloides

Red Flowers

  1. Chuparosa -- Justicia californica
  2. Ocotillo;Coachwhip -- Fouquieria splendens

Pink/Lavender Flowers

  1. Red-stemmed Fillaree -- Erodium cicutarium
  2. Engelmann Hedgehog Cactus -- Echinocereus engelmannii
  3. Fairy Duster -- Calliandra eriophylla
  4. Bigelow's Four O'Clock -- Mirabilis laevis
  5. Wolfberry -- Lycium spp.

Blue Flowers

  1. Eucrypta spp.

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