Hundreds of rescuers, including teams from local, state and federal agencies, as well as volunteers, are involved in the search, Texas Game Warden Ben Baker said Tuesday during a news conference.

Within six years of opening, Camp Mystic was inundated with floodwaters.

Federal regulators repeatedly granted appeals to remove Camp Mystic’s buildings from their 100-year flood map, loosening oversight as the camp operated and expanded in a dangerous flood plain in the y...