Beautiful in every season of the year. There are plenty of well-marked trails that can be hiked from late spring through October. Always go prepared--water, some food, extra clothes (the weather can change suddenly)--a GPS if you're going off trail.  

Plenty of ski slopes to entertain you in the winter months.  Snowshoeing and cross-country skiing on many trails, as well as off-trail. 

There's something for everyone here.  Lake Blanche is a beautiful hike wiith a gorgeous pay-off at the end, but fairly rigorous.  Donut Falls and Silver Lake are very family friendly.  And there is plenty in-between--check for details on the many websites or guidebooks.