Elkhorn Resort Sun Valley is an 18-hole semi-private golf course in Sun Valley, Idaho, built in 1975 and designed by Robert Trent Jones, Jr.. It sits in the $$$$ (splurge) price range for golf in Idaho. The season runs May 1 to Oct 31. Tee times can be booked 2 days in advance. Guests are welcome.
Details like fees and seasons change, so call the course before you head out.