Oh wow, found a little bit of the same rumor.
Publication Date: June 22, 2005
Omak Lake is an ancient body of water, about which the native Indian population holds significant cultural and religious views, which includes sightings of the Omak Lake Monster. The reported Omak Lake Monster had its true believers and debunkers. Since the sightings of the lake monster happen rarely, few native people cared to offer their views, leaving it to the true believers to spread the gospel about the marine lake monster. No one knows whether it is fish, marine mammal, reptile, amphibian or ancient marine dinosaur. Outside the native people, few people believe that a lake monster resides in Omak Lake. The true believers hold that Omak Lake is bottomless, though the lake has been surveyed and mapped many times.
Doubters of the stories of the Omak Lake Monster bring up the legendary Ogopogo, the Okanagan Lake Monster, British Columbia, Canada. They state the local Indians are attributing stories about Ogopogo of Okanagan Lake to Omak Lake. The true believers of the Omak Lake Monster state they are not confused, and they maintain there is a lake monster in Omak Lake. Thought not discounting exploits of Ogopogo, they believe the Omak Lake Monster is real and menacing to anyone not giving it space."
Quote description taken from http://www.amazon.com/Omak-Lake-Monster ... 059535923X
I remember hearing the bottomless part.