You have some great choices in this area, and some very active clubs as well. In no particular order...
Blackscreek Range -
http://www.blackscreekrange.com/ Outside of Boise, very regimented firing line, daily use fee
Gem County Rod and Gun Club -
http://www.gcrgc.org/ Just outside Emmett. Great little range, lots of pistol shooting events, annual membership is cheap, rifle range to about 200 yards if IIRC. Only about a 30 min drive from Boise.
Nampa Rod and Gun Club -
http://www.nragc.org/ Just outside of Nampa. Another great range, pistol pits, rifle pits, organized shooting events about every weekend and during the week. They also have an indoor range in Nampa that is nice to use in the winter. Great place.
Parma Rod and Gun Club -
http://www.parmarng.org/ This one is a bit of a drive, just outside Parma almost to Oregon, takes about 50 minutes to get there from Boise, but IMHO, is a great place to shoot. Pistol and rifle range out to 700 yards and beyond once you get to know the place. Lots of organized shooting from pistol, rifle, 3 gun, long range rifle. Host to some great major matches throughout the year. Ok, I'm biased, this is where I choose to hang my hat and call my home range.
In short, if you want to shoot, either for fun or part of an organized event, you have your choice and options.
