If she exists at all, she would be deep inside the bamboo groves and dense scrub along the San Gabriel River bed, away from human eyes.A mother mountain lion and at least one cub are reportedly roaming the river bed from the Whittier Narrows Nature Center in South El Monte at least as far south as the gate of the Whittier Narrows Dam in Pico Rivera.The cat was first sighted several months ago by motorists, who apparently came across her late one night on a road near the Nature Center, said Mickey Long, natural areas administrator for Los Angeles County Department of Parks and Recreation.Equestrians also report mountain lion tracks and signs of the animal’s kills in the sandy banks and trails of the river bed.“We are undecided yet as to whether we have a mountain lion or not,” Long said. “Large dogs have not been ruled out.”County officials have posted signs in Whittier Narrows warning of possible danger.Long has worked Whittier Narrows since 1971 and has never encountered a mountain lion.“There’s never even been a rumor of a mountain lion track,” he said.Long said the rumored beast could be a bobcat, although there has never been a bobcat sighting in Whittier Narrows that he can remember.Bobcats are much smaller than mountain lions, but larger than domesticated cats. They have short tails, tufted ears and spotted coats. Their diet is mainly smaller animals, such as birds or rabbits.If a mountain lion is roaming the narrows, it would be a surprise to field biologists like Long.Mountain lions typically don’t like to come so close to urban environments, and the game to be had in the river is fairly limited. The place is teeming with rabbits, raccoons, birds and stray dogs, but a mountain lion’s preferred meal is deer. Long said deer are few and far between in the narrows.Equestrienne Pat Cravey is convinced a mountain lion and one cub or more have made the narrows its feeding ground and possibly its home.“We’ve just seen where she’s taken her animals, the bones, we’ve found entrails,” Cravey said.Cravey walks the river bed from the Pico Rivera Sports Arena to the dam twice daily. On her treks she has spotted signs she believes are those of a mountain lion – paw prints, kill sites and feces densely packed with the hair and bone of some unfortunate critters.Recently, Cravey went on a search for the mysterious big cat. On a narrow path of soft sand cutting through the scrub, she stopped to circle a possible paw print.The print fits some of the characteristics of a puma track, its fingertips are rounded and the center of the print resembles a pyramid with the top chopped off.But the area is home to packs of stray dogs – some pretty hefty and as capable of killing a rabbit as any mountain lion. The prints could come from a large dog, Long said.The narrows is packed with predators. As Cravey walked toward the dam, a Red-tail hawk flitted out of a bamboo grove, a coot in its clutches. Signs of life-and-death struggles between creatures of the narrows are visible all along the river bed – from scuff marks in the sands to bleached and forgotten bones.Along the sandy banks of the river, Cravey spotted what could be mountain lion excrement.“That’s probably hers,” she said, taking a closer look.“Nothing but fur and bones,” she said, breaking the dung apart in her fingers. “A high-protein diet. And that’s big. That would probably be her size.”Cravey walked for hours along the sunlight-dappled tracks and trails, the sounds of civilization far away. She’s out there, Cravey believes, and perhaps the cat was watching the whole time.Leaving the river, Cravey came across a fellow equestrienne, Susan MacClean of Hacienda Heights, riding a sleek, auburn appendix quarter horse named Miss Katie. MacClean has traveled the horse trails in Whittier Narrows since 1987, she said.Cravey asked her if she had seen any signs of a mountain lion. MacClean said she hadn’t really looked for any.“Coyotes, yes,” MacClean said. “There’s one out there right now that is the mangiest looking thing.”MacClean said she has noticed a decline in the number of stray dogs roaming the narrows, something she thinks could be caused by a mountain lion, or who knows what.One thing Cravey and Long share, though they have never met, is a desire to help the animal. email@example.com(626) 962-8811, Ext. 2717 AD Quality Auto 360p 720p 1080p Top articles1/5READ MORERose Parade grand marshal Rita Moreno talks New Year’s Day outfit and ‘West Side Story’ remake160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!