Here is the least expensive 6-segment itinerary I could find on the west coast that would qualify for the "fast track" silver or gold medallion promotion. The itinerary can be done in either direction.

RNO - EKO (Elko) on Skywest
EKO - SLC on Skywest
SLC - LAS on Delta

The routing allows a through fare from RNO to LAS and if you stay overnight, the roundtrip fare is $117. You will need to spend about 3 hours in Elko each way, since the shortest connection has the same flight number and would not qualify as an extra segment.

Does anyone have any other good ones, especially ones that start in Calif?