First suggestion:Tacoma Narrows WA (KTIW) to Tieton State (WA49)
Approximately 103 nm. Route leads under part of Seattle Class B airspace then over 6,940 MSL terrain (near Mt. Rainier) to a mountain valley landing on your choice of a 2,471 ft grass strip or an adjacent lake. Destination altitude 2,961. For a litle bit of chalenge, radio navigation requires use of a VOR/DME (YKM) in line with part of, but not along, the planned route. I haven't made my own ETE calculations, the FS 2004 planner estimates 39 minutes. The simulator's planner seems to frequently be a bit low with its first and final leg ETEs though.
Note that the simulator shows 4S6 for the destination airport code.
Robert
Near KORF