The Horde — Jason Henry

Book 1 of the "Peoples of the Arden" series When the Flemming family and their friends go on an end of summer camping trip in the Pacific Northwest, hoping to get a photo of Bigfoot they are suddenly transported to the land of Lindmeara. Lindmeara is a land of elves, dwarves, Kings and wizards. It is also land besieged by the Horde and King Talon believes that only the Flemmings can save them. When the families realize they aren't in Washington anymore they set out to explore their new surroundings. As they meet the inhabitants of Lindmeara they learn that their young daughters all possess magical abilities. They start to suspect that their girls are the reason they were brought there, and when they learn the truth, they have to decide if getting back to earth is more important than trying to help a people in desperate need. If they decide to stay they will need to use all of their knowledge, weapons and skills to survive. Most importantly, their daughters will need to learn to use magic or neither they nor Lindmeara will survive.