Tommy J. DeBardeleben

Tres Rios Wetlands-Hayfield Site (Historical, no longer open to public)

Fast Flight Facts

Target Species:  Desert riparian species, good location for Crissal Thrasher

Elevation: 970'

Habitat:  Riparian habitats surrounded by mesquite desert 

Overall Birding Rating: 5

Difficulty: 1 (Easy)

Birding Type: Easy Hiking

Facilities:  Parking, restroom

Fees/Ownership:  None/City of Phoenix

Closest Town or City/How far from Phoenix:  Tolleson /11 miles southwest of Phoenix

Getting there:  Reached from a dirt road leading to the Wetlands off of 91st Avenue

Overview:  Located off of southern 91st Avenue, the Tres Rios Wetlands is one of the best birding locations in the southwest Phoenix area.  Although a relatively small wildlife area, Tres Rios holds a lot of birdlife.  Habitat here consists of open and reed-lined ponds, cottonwood groves, willows, mesquites, and tamarisk, as well as desert scrub.  It is a peaceful place to go to, and is open daily.  Raptors and waterfowl abound in this desert-riparian area as well as numerous water and songbirds.

Tres Rios is a great spot for seeing a variety of Birds of Prey.  Bald Eagles nest south of the the wetlands on Indian property, but still can be viewed from a distance.  Ospreys are commonly seen, Peregrine Falcons are fairly common.  Other raptors to watch for include Black and Turkey Vultures, Northern Harrier, Sharp-shinned Hawk, Cooper's Hawk, Harris's Hawk, Red-tailed Hawk, as well as American Kestrel and sometimes Merlin.  The ponds here at the wetlands are fairly small, but seem to hold a lot of waterfowl with a good species selection.  Often here are all three teal species: Blue-winged, Green-winged, and Cinnamon, and they can often be seen in close range of each other.   Sometimes Blue-winged Teal counts can be very high reliably, even numbering over sixty birds.  Black-bellied Whistling-Ducks often seem to favor this area as well, although sightings are more occasional.  Wintering ducks like the north most of the two ponds the most, and can produce sightings of Wood Duck, Gadwall, American Wigeon, Mallard, Northern Shoveler, Northern Pintail, and Ruddy Duck.  This is one of the better places to look for Wood Ducks in Maricopa County.  Both Double-crested and Neotropic Cormorants are common here and fly back-and-fourth to the east and the west all throughout the day as if the place is a cormorant flyway.  American White and Brown Pelicans have both been seen here, more often White.  There is a big pond more to the east of the immediate Tres Rios Wetlands that is adjacent to 83rd Avenue, and this is always a good place to check for pelicans and the usual waterbirds. 

The common herons are all here, and also the elusive and uncommon Least Bittern.  Tres Rios is often a great place to see Least Bitterns, scan the reeds carefully, as they tend to be out more in the spring and early summer months.  When birding in the Least Bittern habitat with reeds, keep an eye out for rails as well, as both Sora and Virginia Rail can be seen here.  This is also a great place to see nesting Common Gallinules up close, which is an amazing sight just after the chicks hatch.  Given right water levels on ponds, shorebirds may be present, which includes Black-necked Stilt, American Avocet, Spotted Sandpiper, Greater and Lesser Yellowlegs, Least Sandpiper, Long-billed Dowitcher, and Wilson's Snipe.  Greater Roadrunners and Lesser Nighthawks prefer the scattered mesquites to the east. 

Tres Rios is also a place that is very good for songbirds, both resident and migrating birds alike.  Resident and breeding birds include Black-chinned and Anna's Hummingbirds, Gila and Ladder-backed Woodpeckers, Black and Say's Phoebes, Ash-throated Flycatcher, Western Kingbird, Loggerhead Shrike, Cliff Swallow, Verdin, Rock Wren, Black-tailed Gnatcatcher, Crissal Thrasher, Phainopepla, Lucy's and Yellow Warblers, Common Yellowthroat, Abert's Towhee, Song Sparrow, Northern Cardinal, Summer Tanager, Blue Grosbeak, Red-winged and Yellow-headed Blackbirds, Brown-headed Cowbird, Bullock's Oriole, Lesser Goldfinch, and House Finch.  Migrants and wintering birds to look for are Vaux's Swift, Rufous Hummingbird, Red-naped Sapsucker, Northern "Red-shafted" Flicker, Western Wood-Pewee, Willow, Hammond's, and Pacific-slope Flycatchers; Brown-crested Flycatcher, Plumbeous, Cassin's, and Warbling Vireos; Violet-green and Barn Swallows, Bewick's, House, and Marsh Wrens; Blue-gray Gnatcatchers, Ruby-crowned Kinglet, Hermit Thrush, American Robin, Cedar Waxwing, Orange-crowned, Nashville, Yellow-rumped, Black-throated Gray, MacGillivray's and Wilson's Warblers; Yellow-breasted Chat, Green-tailed and Spotted Towhees, Chipping, Vesper, Lark, Lincoln's, and White-crowned Sparrows; Dark-eyed Juncos, Black-headed Grosbeak, and Lazuli Bunting.  Rare birds seen at Tres Rios on a Maricopa County scale have included Broad-billed Hummingbird, "Red" Fox Sparrow, Northern Parula, Brown Pelican, and the first ever Maricopa County record of Eastern Bluebird.  Bobcats, Coyotes, and Raccoons are some of the other wildlife that may be observed here.

Birding Tip: Tres Rios Wetlands is open daily from 6 A.M. to 1:30 P.M.  Birding here is good in all seasons.  Come early when visiting here, as the morning here is dramatically more productive than an afternoon visit.  Even though good birds can still be seen in the afternoon, it is much more quiet.  If visiting in the winter, start off by going to the north most pond out of the two ponds in the immediate wetlands area.  Ducks gather in large numbers but do spook very easily.  Approach the pond very slowly and scan parts of the pond while walking up to it, in case the flocks do take flight.  After scanning the ducks, work the other parts of the wetlands.  The south pond varies in vegetation, and is often covered by vegetation.  Viewing platforms give the birder chances to see rails and other marsh birds. The cottonwood grove between these two small ponds is a good potential place to hold nice warblers aside from the abundant Orange-crowned and Yellow-rumped Warblers.  A trail that runs beneath the main level of the ponds is a good place to look for raptors in the trailside trees and is an excellent place to look for songbirds resident and migrant alike.  By continuing east in the open shrubby desert habitat past the immediate wetlands gives the birder other good opportunities at open desert species as well as more waterbird habitat as a big pond lies adjacent to 83rd Avenue, which can often hold good waterbirds.  This area has a lot of snags and power poles along the path which offers good raptor habitat.  CAUTION:  The area sometimes has big feral dogs that run loose on to the wetlands area.  Use caution in case these dogs may be around.  Watch for rattlesnakes in the area as well.

Directions:  To access Tres Rios, an easy way to get there would be to take the 91st Avenue exit south if on the I-10 freeway.  Also, if coming from the Loop 101 south, one can merge east onto the I-10 freeway for a short distance to reach the exit for 91st Avenue.  Once on 91st Avenue, take it south for five miles to the Tres Rios turnoff.  The turnoff to Tres Rios is a dirt road that can be accessed on the east side of 91st Avenue.  It is just north of Baseline and 91st, and about a mile south of Broadway and 91st. 


Map of Tres Rios

Tres Rios Wetlands eBird Data


Scenes and Sights from Tres Rios Wetlands:

Winter Months..

Big Pond to the east adjacent to 83rd Avenue (below)..

Summer months..


Birdlife of Tres Rios Wetlands:

Crissal Thrasher

Black-bellied Whistling-Duck

Blue-winged Teal

Cinnamon Teal

Wood Duck

Ash-throated Flycatcher

Black Phoebe

Least Bittern


Bald Eagle

Lesser Nighthawk

Common Gallinule

Black Vulture

Eastern Bluebird-rarity (first Maricopa County record)


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