This is a wonderful old classic, that still holds up very well more than half a century later.
Salmon Ken is an ordinary high school science teacher, who gets recruited by the narcotics cops to help track down the source of a new drug. It's been around in small quantities for about twenty years, but authorities are worried because it is dispersed in the air (making it possible to expose the unwilling) and a single dose is enough to create a powerful addiction. It is, potentially, the most dangerous drug in the galaxy. The narcotics agency persuades him to accept a job with the smuggler, who wants someone with some science background to help him synthesize the drug rather than buy it. The narco cops hope Ken will be able to find the source so they can stop it.
He quickly learns two things. One is that his new employer is completely ruthless. The other is that the source of the drug is a horrifically cold planet--an iceworld.
The Wing family lives very well from the proceeds of Mr. Wing's successful "prospecting"--very success, and not really prospecting, as we soon discover. They spend every summer as Mr. Wing has since shortly after the war, when he stumbled upon an incredible opportunity in the still-wild lands of the west, and had the sense to keep his mouth shut.
He's trading with aliens, getting platinum and iridium (but not gold; it would attract too much attention of the wrong kind) in exchange for something readily available on Earth.
Ken and the Wing family have a lot to learn about each other. The only question is whether they'll survive the process.
I borrowed this book from a friend.