We discovered this park a few years ago as we started making regular trips to Truckee in the summer. It's much less crowded than Lake Tahoe but you still get lakeside activities - you can grab a little spot of beach along the lake or even Donner Creek.
On one visit we rented double kayaks and took our 5 yo and 7 yo out on the lake and they loved it! Our 7yo even tried his hand at paddling.
There is also decent fishing here. Kids may have the most luck fishing Donner Creek and not the lake itself, unless you can get out into the water. Both our kids were very excited to catch their first trout here!
If you time it right, there is some free parking along Donner Pass Road and you can walk in to the park from the road. But it's worth paying the nominal fee to support the park too - and getting to the watersports store or the quiet China Cove area is much faster with a car.
I've been to Donner Memorial State Park many times over the years. The place pays homage to the memory of the Donner Party (a traveling party largely made up of Donner family members) and their tragic end in this beautiful location as they made their way through California during a harsh winter. Much of the Donner story has given way to folklore over the years so go and get the facts from the knowledgable park rangers here. The Donner story is tactfully handled by this staff. You will also come away with a greater appreciation of the landscape around you.
One Trivial Pursuit - type fact that has stayed with me. During the winter the Donners came through the area, the snow level was at the feet of the people depicted on the Donner Memorial. Trust me that is tall (Somewhere around 15 feet)!
Spend a half day here on the way to Tahoe, and get a history lesson too. Beneath towering evergreens at 5,950 feet, walking paths and picnic groves are cool and shady. From here you can access a relatively easy portion of the Donner Lake Rim Trail, a newly established, 23-mile-long, sometimes steep trail crossing ridges and granite knobs; this route also intersects the Pacific Crest Trail. The Emigrant Trail Museum depicts stories of the Donner Party, a group of pioneer families who were trapped here during the violent winter of 1846–47. A monument rests on a stone base 22 feet high—the snow level of that fateful winter. In the museum are artifacts and displays on the building of the railroad through the Sierras in the 1800s. In the distance, you can see train tracks, mostly covered with snow buildings, running along the rugged mountainsides above Donner Lake; the tracks are still in use by Amtrak today.
Rangers guide interpretive walks throughout the summer, explaining local flora and fauna and the history of the Donner Party. In the wintertime, rangers lead free snowshoe history hikes and introductions to cross-country skiing. It’s free to cross-country ski on a 3-mile loop.
This is our families new favorite camping spot! The best camping is in the creekside portion of the campground (shade and a fun creek to play in), and the lake offers so many options. You can just swim, or even rent skidoos, canoes or paddle boats. The nearby town of Truckee is charming and offers lots of family friendly restaurants if like me, you enjoy a few meals out while camping (really, it needs to be a vacation for Mom too!!!). The weather is usually beautiful in the summer, but can get warm. There is a museum and short film that tells the tale of the ill-fated Donner party, for a little education along with your camping. We love this place and camp here each year. Best campsites are 85,86,87. Oh... and the bathrooms are recently re-done, so they are decent (although by the end of the day, the floors get pretty dirty), with nice coin operated showers so bring plenty of quarters. Dogs are allowed, kids can ride bikes very safely around the campground, and the rangers are friendly.
I've spent a good amount of time in recent summers at Donner State Park with kids. It's a great spot for everything from biking to kayaking to swimming or just sitting on the beach. There are lots of "hidden" spots along the lake to give some privacy for families or you can join others on bigger beaches. There is a charge to enter the park- other than that, bring a cooler for lunch and enjoy the gorgeous views!