If you want to head over in that direction, head towards Challis and then turn back to Mackay Res. ( In the direction of Arco), to late for this year, but you have 10-12 " kokes in there and they are fun to catch on light tackle. Depending on where you are coming from, you can go to Arco and then down to Mackay reservior. Always check the weather, you want a big high presure in place without a change coming from a low pushing in or out. Great lake when the wind does not blow.
However, Anderson ranch produces the same size of fish with a much shorter ride from the central valley.