After i graduate from college this May a friend and I are planning a road trip to california starting in chicago. Could anyone give us some advice as to the best way to get out there? I was thinking about doing something along the lines of taking a northern route out there, take pacific coast highway down the coast of california and then take route 66 back. We are planning on either sleeping in my van or camping and buying as much of our food in grocery stores to save cash. Here are a few questions for anyone who has done something like this before:

-I came up with an estimate of about $1300 per person. I figured this out by estimating about $20 per day per person for food, $30 (total) a day for camping/hotel, and I'm guessing the trip will cover about 7000 miles (my car gets about 19mpg highway on the low end with about $1.50 per gallon). Does this seem pretty resonable or should we expect this being more or less expensive?

-What is the best route to get out there? I was thinking about shooting up through South Dakota to see Mt. Rushmore and the Badlands, spend some time in Yellowstone and then Redwood National Park. I plan on taking my time getting out there and stopping at anything that looks interesting but is there anything else on the way that I should definetly stop at.

-Where should I concentrate most of my trip at or on? 4 weeks is a long time but I'm sure I cant see everything.

-What are some stops that I definetly have to make?

Thanks in advance for any advice you might be able to offer.