MITTRY LAKE, AN UNNATURAL REFUGE

MITTRY LAKE A RESURRECTED PLACE FOR THE BIRDS

“Beaver,” Smokey Knowlton said calmly, pivoting his shallow-draw bass boat with practiced ease while a camera-clutching Jim Tallon teetered on his perch. I strained for a glimpse of the beaver gliding through the cattails and bulrushes of the Mittry Lake Wildlife Area, a largely unheralded haven for birds and bass tucked into an abandoned oxbow of the lower Colorado River just north of Yuma. Late light suffused the wind-ruffled surface of the man-made lake. Coots that had spattered away in an ungainly effort to escape our onrushing outboard smacked back down onto the water as Smokey cut the engine. Silence rushed into the void, abruptly punctuated by the squawks of the nettled coots. The wind rustled the rushes, stirring glittering ripples on the light-drenched surface of the lake. Just ahead, the reeds swayed against the wind. The beaver and I locked eyes. His were enormous, almost black, glistening as sleekly as his well-oiled, slicked-back fur once so prized for top hats that trappers nearly exterminated its kind all along the length of the river. I know that cute shouldn't count in nature, that the crayfish and pond scum at the base of the food chain merit equal billing with these bigeyed, baby-faced bark-eaters. But what can I say - he was adorable. The beaver executed a deft U-turn with an underwater flick of his tail that propelled him into the shelter of the cattails lining the bank. We drifted along behind, while Jim's shutter clattered away. With a final glance over his shoulder, the beaver dove. Smokey kicked onthe outboard to follow, but the prop imme-diately fouled on vegetation.

Imperturbably, he cleared the jam. It's hard to picture the event that would prompt Smokey to show alarm on a boat. How can you unsettle a man who has trolled the entire coastline of the United States in a 17-footer and navigated the length of the Colorado for good measure? He's settled down now in a rambling house perched on the bank of Martinez Lake on the Colorado River, where he hand-feeds visitingraccoons, runs river trips for tourists, and occasionally shepherds wandering writers and photographers willing to swap lies and listen to the river.

In this case, he'd promised a leisurely tour of every lazy nook and quiet cranny of Mittry Lake, a refuge for beavers and bird-ers, kingfishers and fishermen. The lake, which includes 350 acres of open water and 3,500 acres of wetlands, desert, salt flats, and riparian woodland, boasts an abundance of 10-pound bass and 30-poundcatfish together with one of the most varied bird populations in the country. Its denizens include large numbers of the endangered Yuma clapper rail and the threatened black rail, sharp-beaked waders whose ranges are limited by the length of their legs and the food among the reeds. Marsh hawks and os-preys patrol the skies; great blue herons and egrets perch in the tangle of snags, and songbirds compete musically with the lap-ping of the water.Despite its biological diversity and ecological complexity, Mittry Lake has suffered a long history of alternating abuse and preservation. Now Mittry is an artificial creation, like most of the Colorado River.

The changes have profoundly altered the ecology of of the lower Colorado. Steamboat crews before the turn of the century fed their hungry boilers with the cottonwoods that once lined the river. The succession of dams that tamed the river's spring floods prevented reseeding of the cottonwoods while helping create both an agricultural empire for Arizona and California farmers and supplying water and power to Sun-belt cities. They also cut off the replenish-ment of nutrient-rich silt on the river's floodplain while simultaneously control-ling some of the most destructive annual floods in the nation.

In addition, salt cedars imported from Asia for windbreaks got into the river sys-tem and opened a war of attrition with the native trees. The salt cedar is a remarkable plant. It grows very fast, sprouts from the root to recolonize areas cleared by fire or flood, and thrives in killingly saline soil. It even drives out its competition by "sweat-ing" salt from its pores, virtually sterilizing the surrounding soil.

Salt cedars have replaced the cotton-wood and willow galleries along much of the lower Colorado, adding to the ecolog-ical transformation started by immigrant settlers in the mid-19th century.

That's why Mittry Lake has become so crucial to the resilient but forever altered ecosystem of the lower Colorado, and why its human keepers keep reviving it.

Laguna Dam began storing water in 1907. Engineers rerouted the river behind the dam, straightening the channel from its historic riverbed. The powerful Colorado no longer wandered into the oxbow that contains Mittry. This isolated bend of the river received water haphazardly for the next 45 years, mostly by seepage from the nearby main river channel.

In 1942 the Arizona Game and Fish Commission leased the lake from the federal government, and the state agency spent the next 10 years building canals from the Colorado to the lake, feeding the marshes with a steady supply of fresh water. Soon thereafter, though, farmers downstream began to use water from behind Laguna Dam instead of water from behind Imperial Dam. With water levels extremely low in the Colorado between Imperial and Laguna dams, Mittry was again without a source of fresh water.

The water supply wasn't stabilized until 1971, when the state and federal governments agreed to build inlets, channels, and levees to provide habitat for migrating birds and endangered year-round residents such as the rails.

The effort hasn't been without pitfalls. A 2,000-acre fire sparked by someone with a flare gun swept through the wildlife area in 1989, fueled by the thick tangle of salt cedars and willows. The cottonwood trees were destroyed, but the salt cedars sprang back. Wildlife managers have now planted 6,000 mesquite, cottonwood, and willow trees, but the saplings are struggling, partly because the beavers quickly gobble up any young trees that aren't protected by an armor of wire mesh.

Soon after the fire, wildlife managers planted two huge clusters of artificial nest platforms mounted on telephone poles, complete with woven nests and cutout birds. So far the egrets and herons evicted from the cottonwoods by the fire haven't built nests in the ungainly structures, but they've become favored perch sites.

MITTRY LAKE

Mittry remains a paradise for waterfowl. The miles of shallow shoreline along the dredged open water help. But the real bonanza for the birds lies in the thousands of acres of marshy shallows on the other side of the dikes, byways so shallow and choked with bulrushes and cattails that even canoeists have difficulty pushing through.

Through these hidden reaches stalk perhaps half of the world's California black rails, little birds out of their depth ecologically in more than a few inches of water. They hunt mostly insects in the shallows, drop two-thirds of their weight rearing their young and surviving the winter, and build cozy nests in the reeds, which they defend ferociously. They're utterly dependent on water depth and bulrushes and remain vulnerable to rapid water-level changes and destruction of their marsh habitat.

The larger crayfish-eating Yuma clapper rail also depends heavily on Mittry, which shelters an estimated 20 percent of the birds' total population. Yuma clapper rails forage in slightly deeper waters in three or four marshy areas along the lower Colorado.

Of course, the intricacies of rail love The Mittry Lake Wildlife Area is located about 10 miles north of Yuma. Take U.S. Route 95 east from Yuma for five miles before turning north onto Avenue 7E (aka Laguna Dam Road). Ten miles later, the road turns to gravel, and soon thereafter you have entered the refuge. For more information, contact the Yuma office of the Arizona Game and Fish Department, (520) 342-0091, or the Yuma office of the Bureau of Land Management, (520) 317-3200. To reach Smokey Knowlton's Yuma River Tours, call (520) 783-4400.

calls are mostly lost on the patient bass fishermen floating on the dredged main channels and flicking their lures up against the overhanging banks that shelter the lurking fish. Mittry is known for its ample supply of 10-pound largemouth bass. Other lakes have more bass, and the big reservoirs have larger bass, but few spots along the Colorado River offer as many of the hard-fighting midsize bass. The voracious bass eat almost anything they can get into their mouths, including most of the native fish. They also provide solid sport for the thousands of fishermen who have dedicated themselves to memorizing the banks and contours of Mittry Lake.

Of course, fishing takes patience.

So does waiting for the kek-burrr of a lovelorn clapper rail.

But, then, that state of mind can become addictive. That's why river rats like Smokey Knowlton can't tear themselves away once they've adjusted their interior pulse to the river's cycles. He reads the water and the wind and the slope of the river bottom like a husband reads the moods of his wife in their 40th year of marriage. Alternately indolent and bursting with energy, Smokey can drift on the current with perfect patience, explode into furious activity, splash through frigid water with nonchalance, spend all day lolling on the ripples, or work all night rebuilding a cranky engine. Into what pigeonhole do you stuff a man who seems without conventional ambition, who pushed through gales and hurricanes to navigate the entire coast of our country?

Suddenly the boat pivoted once again. Barely puttering, we glided toward a peninsula of cattails. I spotted the angular outline of the great blue heron as we approached. The big long-legged bird eyed us skeptically. Then, with a shrug of resignation, it spread its enormous wings, taking a short hop followed by powerful strokes of its sixfoot spread of wings, pinfeathers extended.

In a moment, the bird was skimming across the water, a blue-black shadow aching with freedom and grace.

We three humans sat motionless in the boat, watching the heron dwindle against the faceted sparkle of Mittry Lake in the long last light of the day.