If you can bring your bike, Crater Lake offers some challenging cycling. The Rim Drive is 33 miles long with many hills to tackle not to mention having to deal with heavy traffic during the summer. At least they are likely to not be going too too fast. Even during the winter one can ride from the Rim Village down to the Steel Visitor's Center and beyond to the Annie Springs entrance. Round trip is 14 miles. However there is the matter of the 3.3 miles from the Steel Visitor's Center back up to the Rim Village which has an average gradient of 3.7% with some steeper pitches near the bottom. Definitely a challenge from a low-lander from Richmond, VA!
Equipment: Bike, bike gear (don't forget the helmet!)
There are more than 90 miles of hiking trails in Crater lake. The best time to try them is starting in August as there is too much snow left until then.
Some famous trails:
1) Garfield Peak: 1.7 miles, lead to the 8054 foot peak
2) Mt Scott: 5 miles, highest point in the Lake
3) Watchman: easy 0.7 miles
4) Castle Crest Wildflower Garden: easy 1 mile
5) Cleetwood Cove: 1.5 miles lead to lake shore
More details in the link below