Utah State University is located in Logan, which is approximately a 1.5-2 hour drive from Salt Lake City International Airport, and the same distance from Pocatello (ID) Regional Airport. Salt Lake City International Airport is a Delta hub, but also accommodates both domestic and international flights across a large number of different airlines.
To those flying from the UK, one budget option is Norwegian Air which has no frills flights from London Gatwick to Denver. From there you would have to book an inexpensive hopper flight to Salt Lake City (the cheapest usually offered by Frontier Airlines).
Salt Lake Express runs a frequent and affordable shuttle from the Salt Lake Airport directly to the conference hotel (University Inn) on the campus of USU.
For those interested in car rental, Salt Lake Airport has desks for all major rental companies.