This ride gives access to a beautiful valley where the railroad takes a side-tour to gain elevation in preparation for Donner Pass. As a bonus, you can swim in the lakes.
To reach the trailhead, take Cold Stream Road from Donner Pass Road, and park on the side of the road, next to a tall chain-link fence. After a brief flat portion, the road climbs rather steeply, for the hardest climb of the whole ride. The road then flattens out once in Cold Stream Valley.
You can ride along the main road all the way till the railroad. You can also cross under the railroad: this is fun (and wet) in early Summer, when the stream that also passed under the railroad has water. The road continues up, and you can follow it if you wish, but the ride we describe turns back. Follow the road back till the foot of a short steep descent: there, you will see a marked side-road that takes yo to cross the stream, and to the other side of the lakes. There is private property around the small portion of road that crosses to the other side, so be sure to keep to the road, and not enter the private land (that looks like an industrial yard) to the side.
Once on the other side of the lakes, continue down the valley, and if you wish, choose a nice spot where to have a swim. After the lakes, keep to the left at the fork, so that you will be led to re-join the path you followed up. Be careful going down the steep descent that you had to climb on the way up: the gravel on the road can make the road very slippery.