Indian Creek
Indian Creek flows down the largest canyon on the southeast corner of the Crags. Even in late Fall its flow is more than adequate to qualify as a full-fledged "creek", but there are spots where a portion of the volume seems to disappear underground and re-surface farther downstream. I've only hiked along it in the Summer and Fall, but it must be a very lush, verdant experience in the Spring, because even after a dry year the place is covered in greenery.
The upper section can be accessed from where it's crossed by the Pacific Crest Trail, and indirectly via cross-country travel from several other points along the trail. The lower part is reached by the Indian Creek Nature Trail [shown below], a delightful 1 mile loop beginning near the Park Headquarters.
The upper bridge is where the loop trail crosses the creek and heads back downstream. The hiking is very pleasant and can be done in just about any kind of weather. I recently hiked along the trail in the Fall and noticed that the south side of the trail (left side, facing upstream) was covered with Maple and Dogwood leaves, while the north side was mostly carpeted with Oak leaves. There were signs of bear here and there but few, if any, deer tracks, strangely enough. Aside from the faint freeway noise and the occasional train horn, the creek is the only sound you'll hear.