From the airport you can head down Old 99 to Tenino, take the Tenino/Yelm Trail to Yelm, then take 510 north to, well, Tolmie State Park if you want to go that far north. That is 3/4 of a loop that could come in from 50-75 miles depending on how much of the shoreline you hug working your way back to the starting point.