No, Your likely to encounter snow and even require chains on your vehicle. Plan it for 1st or 2nd week of June sometime. This way you get to see trees and the waterfalls in Yosemite are raging. You'll still see snow in higher elevations, but not on the road.

Here is an awesome link showing you the best of the Redwoods everywhere up and down the coast. I've used this several times. http://www.redwoodhikes.com/
Notice he only gives a few places 5 stars*****

Just so you know. Redwoods National Park is made up of 3 State Parks(I don't know of any other National Parks like this). Jedediah Smith and Prairie Creek are my favorites. James Irvine Trail that connects with Fern Canyon Trail is one of my very favorite hikes of all time(I've been to 34 of our 59 national parks and hiked most of the major trails at them). I hiked it both ways with my 9 year old nephew. You could hike it one way and have someone meet you at the ocean/fern canyon with a car. Fern Canyon alone is an amazing place. James Irvine/Fern Canyon to the ocean is an easy hike and 4 miles one way. A shorter hike is The Stout Grove that is also nice. You are likely to encounter elk around Prairie Grove. James Irvine Trail starts near the visitor center.

When I said No--That was for Sequoia and Yosemite that you could run into snow.

Big Basin, Armstrong, Humbolt, and Redwoods National Park could be foggy, raining but thats the way it is a lot of the time anyway. That's why the trees are so big and the rain forest so cool to look at. The constant precipitation is good for them

Here are some photos with my nephew. This was July 2010. The first photos are of Lassen Volcano National Park.

Photos 63 thru 73 are of Patricks Point State Park. This is an awesome place. Go at lowtide and go tidepooling. 74 thru 97 are James Irvine and Fern Canyon all the way to the ocean.
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If you decide to stay close to San Fran and do Muir, then consider spending the better part of the day at Point Reyes.
Go tidepooling somewhere at Point Reyes too. If you do Big Basin, then go sea-kayaking at Elkhorn Slough not far from Monterey. You and your son would love Monterey Bay Aquarium.


For comparison, here are some photos with my wife and our daughter of Sequoia in January 2008. http://share.shutterfly.com/action/w...0IatW7FqybsWoQ

I still find photo #25 on Sequoia totally amazing. The tree next to the museum puts it into perspective.

Here are some of Muir Woods and Point Reyes. Spring Break 2009
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A few in San Francisco Spring Break 2009
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I forgot my good camera on this trip and this was one of those cheapies, so quality isn't that great

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Here are a few in Big Basin with my wife, plus Monterey, Big Sur, Hearst Castle. Elkhorn Slough is at the end.

There are great tidepools in Santa Cruz as well at Natural Bridges State Park. North of there is Ano Nuevo State Park where the elephant seals are.

>> Could we get to Sequoia National Park (mid-march) where the biggest trees are without dealing with snow and winter weather?<<

We were in Yosemite & Sequoia in April '11. The entrance to Yosemite that is on fire now was completely closed because of snow. Chains and 4 wheel drives were not allowed. When we got to Sequoia, we had to put chains on our car to enter the park.

Stu Dudley