It really depends on what you prefer for your trip (waterfalls, views, etc). There are many great trips in the Yosemite area. For a 3 day itinerary the Mist Trail to Little Yosemite to Sunrise Creek and out to Tenaya Lake via Clouds Rest is pretty hard to beat. The North Rim is a good route that you can stretch into 3-5 days. Glenn Aulin is beautiful and you can easily do 5 days by going into the Northern area from there. As far as a reasonable daily mileage that is entirely dependant on your abilities and desires but I would plan for about 10 miles per day depending on the terrain. Cheers and enjoy your trip!
... View more