Gateway is a famous book. It’s one of the few novels that won 4 major prizes: the Hugo, Locus, Nebula and Campbell award, and it’s on numerous essential SF lists.
While it’s perfectly self-contained, Pohl wrote 5 sequels: Beyond The Blue Event Horizon (1980), Heechee Rendezvous (1984), The Annals Of The Heechee (1987), The Gateway Trip (1990) and The Boy Who Would Live Forever (2004). Together with the 1972 novella The Merchants Of Venus, and The Gateway Trip – a short story collection that appeared in 1990 – these books form the Heechee saga.
The Heechee are a mysterious alien race that explored our Galaxy hundreds of millennia ago. Near Earth, they left structures on Venus, and – crucial for this novel – a space station in an asteroid, including functional spaceships. Humans can operate these, but don’t really understand the technology.
The basic premise of Gateway is brilliant: humans embark on voyages in these ships, but it’s a bit of a lottery. Most of the time, crews do not know where they’ll end up – there might be proverbial gold at the destination, but more likely it’ll be just a barren planet, or worse, mortal danger. The link with prospecting in the Wild West is easily made.