Steven Gould is currently best known as the author of Jumper, the SF novel about teleportation which was recently made into a film. It's a very good book (and I hope to re-read and review it here someday) but everything I've read about the film convinces me not to bother watching it, as Hollywood seems to have surpassed even its remarkable record of achievement in turning good books into poor films.
Anyway, to Wildside: Charlie Newell is a young American who has recently inherited a farm from his long-lost uncle. Close to the farmhouse is a large barn which backs into a small hill. Charlie finds a concealed doorway leading to a wide tunnel through the hill, and on the other side is another world: an alternative version of Earth, in which humans have never lived. Huge herds of bison roam, pursued by sabretooth cats, while vast flocks of passenger pigeons darken the sky.
Charlie is an unusual 18 year old; thoughtful, resourceful and rather obsessive about careful planning. With the aid of some friends he sets out to make his fortune from his discovery. With no roads this requires air transport, so Charlie's team qualify as pilots and drag disassembled planes through the tunnel to use on the Wildside. There is a lot of detail about light-plane flying and parachuting, which the author has evidently researched thoroughly. Needless to say, all does not go smoothly, especially when the authorities begin to suspect that there's something odd going on. All Charlie's wits and determination are required to keep ahead of his opposition.
The story is told in the first person by Charlie, and as he is a modest and unassuming guy the style is very matter-of-fact. Indeed, it is a plain, conventional and rather old-fashioned kind of tale, but is none the worse for that. The adventures which befall him and his friends are more than dramatic and exciting enough to grip any reader's attention and make the book difficult to put down until the unexpected, sobering but very topical conclusion.
The story is also about growing up, and learning to cope with relationship problems and the adult world. It succeeds admirably on all counts, and can be warmly recommended to readers of all ages.