Also, see eBird Hotspots in California:
Havasu NWR (CA)
Havasu NWR--Topock Gorge (CA)

From desert bighorn sheep to the endangered southwestern willow flycatcher, birds and other animals at Havasu National Wildlife Refuge rely on the life-giving waters of the lower Colorado River. The refuge protects 30 river miles, 300 miles of shoreline, from Needles, California, to Lake Havasu City, Arizona. One of the last remaining natural stretches of the lower Colorado River flows through the 20-mile-long Topock Gorge. A great river in a dry, hot land attracts wildlife and people like a powerful magnet. Today, many thousands of visitors annually flock to the refuge to boat through the spectacular Topock Gorge, watch waterbirds in Topock Marsh, or hike to the Havasu Wilderness Area. 

Most of Havasu National Wildlife Refuge is in Arizona on the east side of the Colorado River. The refuge office is located on the west side of the river in Needles, California. On holidays, after hours, and on weekends, a self-serve kiosk with refuge brochures and leaflets can be accessed by visitors in front of the administrative office. 

The refuge can be accessed from many different places, including from the Lower Colorado River via boat and multiple roads.  

Also, see Birding Arizona's West Coast from the Arizona Field Ornithologists for tips for birding several locations within Havasu National Wildlife Refuge.

The distinctive kek-kek-kek of the Yuma clapper rail echoes across the 4,000-acre Topock Marsh. Endangered razorback suckers swim in the backwaters of Beal Lake. Bell’s vireos buzz in the surrounding vegetation and hundreds of waterfowl descend into Pintail Slough, a restored wetland. Doves and snow geese rest in the agricultural fields planted with wheat, rye, and millet. Coyotes, foxes, and bobcats cross the roads searching for rabbits and mice. Desert bighorn leap nimbly from steep rock faces along one of the last remaining natural stretches of the river, the 20-mile Topock Gorge. Elusive mountain lions roam and thousands of bats emerge from historic mines in the 17,600-acre Wilderness Area. 
 
Havasu National Wildlife Refuge is a birding hotspot with 318 bird species relying on diverse habitats. Western and Clark’s grebes perform synchronized dances in the waters of Topock Marsh and Beal Lake and nest in the emergent vegetation. Native stands of Freemont’s cottonwoods, coyote willow, and Goodding’s willow provide breeding and stopover habitats for many species of birds, such as the summer tanager and yellow-billed cuckoo. Mesquite and salt cedar thickets support ash-throated flycatchers, Bell’s vireos, and Abert’s towhees. Upland desert areas are filled with coveys of Gambel’s quail and darting greater roadrunners.  Peregrine falcons plummet up to 150 miles per hour between the cliffs in Topock Gorge. 

Havasu National Wildlife Refuge, originally named Havasu Lake National Wildlife Refuge, was established by Executive Order by President Franklin D. Roosevelt in 1941 for the primary purpose of providing migratory bird habitat. The refuge is comprised of 37,515 acres along the lower Colorado River in Arizona and California. The refuge protects 30 river miles and encompasses 300 miles of shoreline from Needles, California, to Lake Havasu City, Arizona. One of the last remaining natural stretches of the lower Colorado River flows through the 20-mile-long Topock Gorge. 

Havasu National Wildlife Refuge is within the Pacific Flyway, a major north-south migratory route along the western coast of the United States. Hundreds of birds stop here to rest and refuel during their long journey. Many species also breed and overwinter here. Because of its importance to birds, the refuge is considered an Important Bird Area in the state of Arizona.

Historically, the Lower Colorado River wound its way through desert valleys and canyons surrounded by a dense riparian forest. Periodic flooding rejuvenated the landscape into a mosaic of willow and cottonwood trees and brought the dry desert to life. Wildlife thrived in the backwaters and forested habitat supported by the mighty river. However, with the construction of the Hoover Dam in 1936 and several other dams along the lower Colorado River, the natural restoration of the desert riparian habitat ceased. 
 
Havasu National Wildlife Refuge protects the remaining native riparian area and the surrounding desert upland and manages the landscape to provide habitat for endangered species and neotropical migrants.

There are several trails at Havasu National Wildlife Refuge:
Needles Mountain Trail - 0.62 mile
Mesquite Bay South Trail - 1.14 mile
Castle Rock Trail - 0.25 mile
Dive Cliffs Trail - 0.14 mile
Mesquite Bay North Trail - 0.23 mile