The Redding/Spy Rock Loop begins in the NE section of the Redding Campgrounds. Ample parking is available, and there is a $3.00 day-use fee you should pay.
The first 10 minutes is a trail through taller weeds, a low area that stays wet and is most filled with bugs/spiders/ticks. Once you get to the loop you have the choice of going right or left....highly recommend going left, the trail to the right is very rocky and best going downhill coming in from the other direction.
Once you get on the loop, starting to the left, it's a clean trail, easy to follow. There are a few creeks to cross with little to no water most days. A timber rattler made a sound behind a few rocks, otherwise a great hike, uphill for an hour and a half.
At the top of the peak there is the spur trail to Spy Rock. It is well designated by a sign, and you'll go left off the loop on the spur trail. This trail crosses a road (I suppose you could skip the loop trail and just take the spur to Spy Rock if you wanted) and then goes about 200 yards to Spy Rock.
Great views at Spy Rock, and you can climb down to different ledges and crags fairly easily. Climb back up where you came down and see where you put your hands before putting your hands on rocks... I went down a cliff to climb up a different way, pulled myself up a few rocks....only to be greeted by a large Eastern Rattlesnake, curled up, rattling and mouth open looking at me as I came up from below. I immediatly let go and slid down rocks to the bottom. That rattler gave me grace, could have bit my hands or face! Lesson learned!
The trail back on the loop isn't very exciting, lots of rocks. There are a few deer in the area, you will most likely scare a couple up to run. Keep an eye open for the trail back to the campground, you'll take a left and go back through the weeds and bugs.
The view is well worth the climb, it's a good trail, easy to follow and challenging enough to keep your interest. Keep your eyes open for the rattlers... enjoy the view and breeze on Spy Rock!