"He's really, really funny," was the immediate description of Christopher Marks' mother, Elizabeth Combs, about the missing 12-year-old from Affton. Marks has been missing since Sunday evening from the Meramec River in Pacific Palisades Conservation Area near the Eureka-Pacific borderline.

Search crews worked through the night, but were unable to locate Marks or any clues to his whereabouts.

Combs said Marks was a Boy Scout, and that his troop members eagerly are waiting for St. Louis County search teams to allow volunteers to assist. "Even his school nurse has called," she said.

She said he recently got a buzz cut, so may look differently than the photos available; he also likely would be walking around barefoot and shirtless. She said he nearly always wore athletic shorts, and had either blue or black shorts on yesterday before he went missing.

Marks will turn 13 years old on Sept. 21. He will be a seventh grader at Rogers Middle School in Affton. He has a twin sister, Anna-Marie, who is "attempting to initiate twin telepathy" to help locate him.

Combs was not present when the incident occurred, but her husband, Marks' stepfather, was with the group who had been picnicing and enjoying Sunday evening near the river. She said the abundant foliage of the tree-laden area challenged the ifrared technology of the search helicopters last night, so family members hoped the search crews would have better luck in today's bright light ambiance.

For more, read Patch's coverage:

• Police Search for Missing Affton 12-Year-Old Boy
• Search Continues for Missing Boy in Pacific, Lip Balm Found May be His
• Video: Bloodhounds, Divers On Scene to Find Missing Affton Boy
• Christopher Marks Missing; Friends, Family Community Reacts Online