White Tank Mountains Park
Litchfield Park, ARIZONA

White Tank Mountain Park offers West Valley residents a vast area of Sonoran Desert and mountain hiking with easy access. It lies at the far west of the Phoenix Metropolitan area (This statement is quickly becoming false as new communities are constructed on the far west side of the White Tanks). Reach the park by driving west on Olive Ave from Glendale through farmland, orchards and open spaces needed for Luke Airforce Base. The park entrance is at the end of Olive Avenue. This is the largest of the Maricopa County parks occupying nearly a full 6 mi. x 6 mi. section. Park elevation ranges from 420 m up to 1200 m. There are four main trails up into the mountains. From the park entrance at the south they are Goat Canyon, Waterfall Canyon, Mesquite Canyon, and Ford Canyon.

The geology across the range is complex. Along the eastern slopes where the trails begin there is granitic pluton formed in the late Cretaceous to early Tertiary periods. Further west ancient metamorphic terraine composed of schist and a wide variety of other minerals. Find more detailed geologic information by ASU Professor Steven Wood.

View from Black Rock Loop Trail at White Tank Mountains Park. This outcrop of boulders is derived from granite plutons formed during the late Cretaceous or early Tertiary periods.

Map of White Tanks and Vicinity

Directions: From Phoenix drive west on Dunlap which becomes Olive Ave. though Glendale. From the intersection of Olive and Grand Ave. it is some 27 km (16 miles) to the park entrance continuing on Olive. Thus it might save time to drive Loop 303, Estrella Pkwy. and exit at Olive and continue west. Nearby areas on the Sonoran Desert Naturalist include Hedgepeth Hills in Glendale and Estrella Park s. of Goodyear. Find more information about visiting the park at the official Maricopa Parks page.

Field Trip Report:
January 29, 2011

There was some rain here back in Nov-Dec 2011 and since then it has been dry and quite mild with little or no winter frost. Trees and shrubs were green with foliage and creosote bush were putting forth some yellow flowers. Ocotillo were in leaf - these woody plants readily drop their leaves after frost of severe drought - thus they can be used to guage recent weather events. A few plants had open flowers but it was necessary to search for them and most were very diminutive.

I noticed that virtually every saguaro cactus had a swarm of minute dipterans (gnats/flies) near the top of the plant and on the sunny side. It was late afternoon with temperatures around 20°C. These swarms are made up almost entirely of males - each swarm included 100 or more. Each male continues circling around while trying to maintain a central position in the group. Presumably female flies are attracted to the group and select a male at the approximate center. They could be seen easily by looking towards the sun while blocking the direct rays from the eyes. I could not tell the species nor do I know what role these flies play in the desert ecosystem. Likely though they live as larvae in the soil or within dead plant material.

I spotted a wine-colored Desert Harvestman, with a globular body about 7 mm long and equipped with eight, very long spindly legs. These are arachnids, related to spiders, but lacking two hallmarks of spiders: no venom and no silk spinning. Another insect I saw in abundance were skeletonizing leaf beetles on the spring foliage of brittlebush. Because spring rains have been so sparse the plants will not lose a lot by letting these leaves be eaten by herbivores.

Sept. 7, 2009

The most brutal heat of summer was beginning to ease so we went out to for an early morning stroll and found it at Black Rock Loop Trail (GPS: 33.50216N, 112.50216, elev = 446m). Our most pleasant sighting of the morning was a doe Desert Mule Deer. There were a lot of ceratopogonids coming to our ankles and ears in search of a blood meal - surprising, unexpected and unpleasant! Even though there had been rain the past week or so the only blooming plants found were Needle Grama (Bouteloua aristidoides), Skeleton Weed (Eriogonum deflexum), Desert Senna (Senna covesii), and Compass Barrel (Ferocactus cylindraceus). Two butterfly species were seen on the wing: Orange Sulphur (Colias eurytheme) and Sleepy Sulphur (Eurema nicippe).

The soil was wet just below the surface suggesting that good desert growth should occur over the next week or so. At the trail head there is a dedicated bench in the shade of a lovely Desert Ironwood (Olneya tesota) in honor of Carl & Margarite Schuetze. On the day we also snapped a photo of a Bendire's Thrasher high on a saguaro cactus. It was singing as were the numerous Black-throated Sparrows. All around this short loop (less than one mile) we did not see a single ocotillo.

Field Trip Report:
March 24, 2002

One of the driest winter seasons in many years has left the Sonoran Desert nearly devoid of greenery. A few creosote bush near the parking areas had flowers and a smattering of ocotillo had bright red blooms at the tips of their coachwhips. Woody shrubs and trees were devoid of fresh leaves and many were already aborting branches and twigs. A reminder of how harsh the desert can be.

Nonetheless, most of the common spring birds and several lizards (Side-bloched and Tree) were spotted along Goat Camp Trail. The trail head is at the first turn off to the left after entering the park.

 

Creosote Bush leaves may yellow significantly during drought and still revive later. If drought continues more and more leaves will die, fall and even some twigs may die back, but the plant will usually survive until rain returns.

Spring Birds

In general order of abundance:

1. Rock Wren -- Salpinctes obsoletus -- Very common little birds which frequently give spirited high pitched trills while perched atop prominants. Their drab gray and brown color blends perfectly with the desert colors.
2. House Finch -- Carpodacus mexicanus -- Males have red on head and chest and do a lot of singing
3. Curve-billed Thrasher -- Toxostoma curvirostre -- Large brown bird with long, conspicuously curved bill and yellow-orange eyes. Beautiful singer.
4. Black-throated Sparrow -- Amphispiza bilineata -- Lovely birds with a jet-black throat and bib contrasted by bright white eye brows. Beautiful singers. A very nice description of the black-throated sparrow can be found at Twentynine Palms Cyberzine (California).
5. Verdin -- Auriparus flaviceps -- Tiny birds, barely larger than a hummingbird. Drab gray brown with a majestic yellow head.
6. Phainopepla -- Phainopepla nitens -- glossy black bird with conspicuous crest and red eyes. White patch visible in wing when it flies. Females are gray in color
7. Gambel's Quail -- Callipepla gambelii --
8. Anna's Hummingbird -- Calypte anna -- Common. Green back; forehead and throat of males magenta.
9. Black-tailed Gnatcatcher -- Polioptila melanura -- Fairly common in the bigger washes where the trees grow a bit larger.
10. Cactus Wren -- Campylorhynchus brunneicapillus -- These birds require more food than would normally be available in this sparse habitat, and so are generally restricted to areas near the picnic tables and campgrounds where they find supplemental food in the form of crumbs and handouts.
11. Ash-throated Flycatcher -- Myiarchus cinerascens -- upright posture with yellow on belly and rufous in tail. Nests in Saguaro Cactus holes.
12. Mourning Dove -- Zenaida macroura --
13. Canyon Towhee -- Pipilo fuscus -- large brown sparrow.
14. Brown-headed Cowbird -- Molothrus ater --
15. Gila Woodpecker -- Melanerpes uropygialis -- Common woodpecker that builds nest holes in the Saguaro Cactus.
16. White-crowned Sparrow -- Zonotrichia leucophrys -- abundant in winter, now migrating back north leaving just a few straglers
17. Ruby-crowned Kinglet -- Regulus calendula -- found foraging in a lone cottonwood at goat camp.
18. Common Raven -- Corvus corax -- Conspicuous, fairly large, jet black birds that soar above looking for food.
19. Gilded Flicker -- Colaptes chrysodes -- A larger woodpecker than the Gila with a distinct black bib.
20. Brewer's Sparrow -- Spizella breweri -- winter bird now migrating back north leaving just a few straglers
21. Sharp-shinned Hawk -- One seen soaring overhead. Feeds on other birds.

Curve-billed Thrasher

Other Vertebrates

1. Side-blotched Lizard -- Uta stansburiana
2. Western Whiptail -- Cnemidophorus tigris
3. Ornate Tree Lizard -- Urosaurus ornatus
4. Desert Mule Deer -- Odocoileus hemionus
5. Rock Squirrel -- Spermophilus variegatus

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Western Whiptail Lizard, Cnemidophorus tigris, often seen tunneling beneath desert shrubs.

Saguaro Cactus

Teddy Bear Cholla

More common species first:

1. Buckhorn Cholla (Cylindropuntia 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. Teddy Bear Cholla (Cylindropuntia bigelovii) -- The joints frequently fall off and begin rooting and may grow into new plants.
5. Desert Christmas Cactus -- Cylindropuntia leptocaulis -- bright red fruits retained on plant for much of the year
6. Engelmann Hedgehog Cactus -- Echinocereus engelmannii
7. Pancake Prickly Pear -- Opuntia chlorotica -- upright prickly pear with distinct trunk. At least 3 km up trail.

Shrubs and Trees

In general order of abundance:

1. Triangle-leaf Bursage -- Ambrosia deltoidea -- The most abundant plant on the lower bajadas. Often leafless after periods of drought or hard frost.
2. Creosote Bush -- Larrea tridentata
3. Foothills Palo Verde; Yellow Palo Verde -- Parkinsonia microphylla -
4. Ironwood (Olneya tesota) -
5. Jojoba -- Simmondsia chinensis -
6. Wolfberries: Anderson Thornbush;Wolfberry -- Lycium andersonii & Wolfberry -- Lycium exsertum -- at least two common species, 1 to 2 meter tall shrubs
7. Lance-leaf Ditaxis -- Argythamnia lanceolata
8. Desert Globe Mallow -- Sphaeralcia ambigua - Bears peach colored blooms after periods of rain otherwise it is difficult to find
9. Brittlebush -- Encelia farinosa -
10. White Bursage -- Ambrosia dumosa - lower flat areas
11. Velvet Mesquite -- Prosopis velutina - within larger washes & canyons
12. Desert Lavender -- Hyptis emoryi -
13. Janusia Vine -- Janusia gracilis - a twisty, viney plant
14. Joint Fir -- Ephedra aspera -
15. Ocotillo;Coachwhip -- Fouquieria splendens
16. Desert Rose Mallow -- Hibiscus coulteri

Triangle-leaf Bursage, Ambrosia deltoidea is one of the most common shrubs at the White Tanks.

March & April Spring Flowers

Yellow Flowers

1. Brittlebush -- Encelia farinosa
2. London Rocket -- Sisymbrium irio
3. Asian Mustard;Sahara Mustard -- Brassica tournefortii
4. Desert Marigold -- Baileya multiradiata
5. Creosote Bush -- Larrea tridentata

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Cryptantha

Orange Flowers

1. Orange Fiddleneck -- Amsinckia intermedia
2. Desert Globe Mallow -- Sphaeralcia ambigua
3. California/Mexican Poppy -- Eschscholzia californica
4. San Felipe Marigold -- Adenophyllum porophylloides

White Flowers

1. Arch-nutted Comb Bur -- Pectocarya recurvata
2. Cryptantha -- Cryptantha
3. Ragged Rock Flower -- Crossosoma bigelovii
4. Lacepod -- Thysanocarpus curvipes
5. Peppergrass -- Lepidium lasiocarpum
6. Lance-leaf Ditaxis -- Argythamnia lanceolata
7. Desert Windflower -- Anemone tuberosa
8. Shrubby Bedstraw -- Galium stellatum

Blue Flowers

1. Eucrypta spp.
2. Lupine -- Lupinus sparsiflorus
3. Blue Dicks -- Dichelostemma capitatum
4. Blue Fiesta Flower -- Pholistoma auritum

Red Flowers

1. Ocotillo;Coachwhip -- Fouquieria splendens

Pink / Lavender Flowers

1. Red-stemmed Fillaree -- Erodium cicutarium
2. Desert Globe Mallow -- Sphaeralcia ambigua
3. Desert Lavender -- Hyptis emoryi
4. Bigelow's Four O'Clock;Desert Wishbone Bush -- Mirabilis laevis
5. Engelmann Hedgehog Cactus -- Echinocereus engelmannii

Green Flowers

1. Triangle-leaf Bursage -- Ambrosia deltoidea
2. Canyon Ragweed -- Ambrosia ambrosioides
3. Jojoba -- Simmondsia chinensis
4. Indianwheat; Woolly Plantain -- Plantago ovata
5. Hairy Bowlesia -- Bowlesia incana
6. Pellitory -- Perietaria hespera
7. White Bursage -- Ambrosia dumosa