Boise Airport (BOI) sits 5 km from downtown and handles direct flights from most western US hubs as well as connections to Denver, Chicago, and Dallas. Alaska Airlines, Delta, Southwest, and United all serve it; the terminal is small enough that it is genuinely quick to pass through. Car rental is available at the airport; taxis and rideshares connect to downtown in about 10 minutes.
By road, Boise sits on I-84 on the western edge of Idaho, making it accessible from Portland (475 km west), Salt Lake City (540 km southeast), and Twin Falls (200 km east). Greyhound buses serve the city, though connections are infrequent compared to larger western cities.