Begin the day by packing a picnic lunch or picking one up at a Jackson eatery. Arrive at Craig Thomas Discovery and Visitor Center in time for a 9 am, two-hour, guided Snake River scenic float trip (make reservations in advance with one of the half-dozen outfitters that offer the trip). When you're back on dry ground, drive north on Teton Park Road, stopping at scenic turnouts—don't miss Teton Glacier—until you reach South Jenny Lake Junction.
Park at the Jenny Lake ranger station and take the 20-minute boat ride to the west shore boat dock for a short but breathtaking hike to Hidden Falls or Inspiration Point. Return to your car by midafternoon, drive back to Teton Park Road, and head north to Signal Mountain Road to catch an elevated view of the Tetons. In late afternoon descend the mountain and continue north on Teton Park Road.
At Jackson Lake Junction, you can go east to Oxbow Bend or north to Willow Flats, both excellent spots for wildlife viewing before you head to Jackson Lake Lodge for dinner and an evening watching the sun set over the Tetons. Or if you'd like to get back on the water, drive to Colter Bay Marina, where you can board a 1½-hour sunset cruise across Jackson Lake to Elk Island. You can reverse this route if you're heading south from Yellowstone: start the day with a 7:30 breakfast cruise from Colter Bay and end it with a sunset float down the Snake River.