Penner Lake offers some of the best fishing in the Grouse Ridge area, partly because there are so many other lakes closer to trailheads that divert anglers before they get to Penner Lake. An hour and a half of hiking with some moderate elevation changes will bring you to this lovely little lake along the Crooked Lakes Trail.
To reach Penner Lake from Highway 80 west of Donner Summit, take the Highway 20 exit and follow it west 4 miles until you come to the turnoff to Bowman Lake. Follow this paved road 8.2 miles to the turnoff to Carr Lake. Travel on a slow, bumpy dirt road for 3 miles to a trailhead parking area at Carr Lake. 4-wheel drive is not necessary unless spring snow is still on the road, but high clearance is a plus. (34 minutes travel time from Hwy 20 to Carr Lake.)
The hike to Penner Lake is a little over 3 miles. Keep your rod handy since you will be tempted to do a little fishing along the way. Start at the Carr Lake trailhead and hike 1 mile past Freeley Lake to the trail junction near Little Island Lake. Watch for the sign that says Crooked Lakes Trail. Turn left there and hike 1 mile, past Island Lake and past a small ponds. At that point the trial begins a stiff climb up a rocky ridge, affording you great views to the south of the Grouse Ridge area.
Once you cross the ridge you will begin a gradual descent that will lead you to Penner Lake. The trail passes along the east shore of the lake, but I would suggest that you turn to the west as soon as you see the lake and angle down to its southern shore. That's where I found my best fishing, getting my first strike in fifteen seconds and my first fish within five minutes. I found good fishing all along the south shore of Penner Lake and around on the west side. Time ran out before I could work myself out to a peninsula (almost an island) on the east side of Penner Lake.
I used only flies at Penner Lake, having my best luck fishing with a #14 Adams:
Lodging is available at nearby Cisco Grove, Soda Springs, or Norden. You also could go over Donner Pass to Truckee where you will find a really comfortable Holiday Inn Express.
Campsites can be found at Carr Lake, Lake Spaulding, Rucker Lake, and Lindsey Lake. The only nice backpacking campsites I found at Penner Lake were too close to the water to be legal. You might consider camping back at Island Lake or continuing along the Crooked Lakes Trail to Rock Lake, another mile north. There at Rock Lake camp on the south shore.
A good selection of fishing supplies, camping gear, and food can be purchased in Nyack, only a few miles west on Interstate 80 from the Highway 20 junction. The store is open 24 hours a day. A gas station and Burger King are located there also. Cabela's has a large store in Boomtown, just across the border in Nevada along Interstate 80. If you are coming up Highway 49/20 you could stop in Nevada City and pick up a great selection of flies and other fly fishing gear at Nevada City Anglers on Broad Street.
Hiking just west of Penner Lake you reach a notch which looks down on Culbertson Lake. A steep cross-country descent would bring you to its shore, but the return hike would be strenuous. Only experienced cross-country hikers should attempt it. A safer way there would be to follow the Crooked Lakes Trail on to Rock Lake and then swing west on the Lindsey Lake Trail. Better yet, drive to Lindsey Lake and hike less than 2 miles to Culbertson Lake. Some people carry light boats in to the lake.