The trailhead for Red Rock begins at the very end of Paradise Rd. There is a large parking area there, recently upgraded with porous, brick parking spaces.
Look for a large metal gate at the north-ish end of the parking lot, near the bathrooms. Pass through the gate and head toward to river. Walk along the cobbles of the dry river bed. Cross the river (it can get deep) and head up the hill. The swimming hole and the red rock that gives Red Rock its name are to the right.
One thing about Red Rock is it is hard to find a place to lay your towel. Make sure you brought enough water and sun tan lotion. You can get very dehydrated here in the summer and you definitely do not want to drink this water!
To get back to the car, go back the way you came. Total mileage: about 2 miles round trip.
A loop option to Gibraltar Dam, returning via the creek
This is a loop hike, about 6 miles round trip.
In the parking lot, look for another metal gate at the west end of the lot. You would find this gate if you drove across the creek and just went straight ahead. Pass through this gate and begin an uphill climb along a dirt road.
At the second bend in the road, about the 3/4 mile mark, you may see a small trail off to the right. It is a shortcut. If you don't see it, just continue along the road.
At the top of the climb, you'll have a nice view toward Gibraltar Lake. As you continue on the road in a westerly direction, you'll have ample opportunity to look at the lake and dam.
Eventually the road drops down toward the dam. Near the bottom, at about 2.75 miles, there is a junction with Devil's Canyon Trail. You may not see it. It's a nice trail along a creek. You WILL see the creek, or at least a sluice gate in the creek near the bottom of the hill.
Near the sluice gate, which is a metal gate with cables that appears as if it controls the flow of the small creek, there is a three-way junction. If you head up the hill you can go see Gibraltar Dam. There's a picnic table and porta-potties and an interpretive sign near a Quonset hut at the top of the hill. That's one option for your hike.
At the sluice gate, if you instead head down toward the creek and make a left turn, you can hopefully find the trail crossing the creek within the reeds choking the creek. At some times of year the trail is under water. Get used to it because if you continue this way, you will be crossing the creek many times and most of the times it will be difficult if not impossible to keep your feet dry most of the year.
The trail is more apparent at the other side of the creek. Follow the trail all the way back to the parking lot where you left your car as it criss-crosses the creek. At times along the trail you will find great swimming holes. Many of them are great for swimming.
Near the end of the trail, before you arrive back at your car, you will come upon a section of the trail where the rocks are rust red and grayish green. To the left will be a rocky swimming hole that some weekends will be full of young people. There's a large red rock that gives Red Rock its name. It's possible some weekends to see brave/foolish young people on top of the rock trying to work up the courage to jump.
Another mile, probably less, and you will be back at your car.