I haven't spent much time in Canada, but I'm very familiar with budget road-tripping in the western states. (In fact, it's kind of my specialty...)
If you're interested in camping, there are almost always campgrounds in the National Parks, and frequently campgrounds in the US Forests. The USFS campgrounds usually have some manner of toilet/vault toilet, and sometimes water. If you're willing to camp even more rustically than that, it's free to camp in USFS forests and BLM land, as long as you're off the main roads. (There are, though, no amenities of any kind.)
If you're visiting over 3-4 National Parks, you should buy a Parks Pass. (
http://www.nps.gov/fees_passes.htm ) It's $80, but allows you to get into all National Parks/Monuments/whathaveyou for free. Totally worth it.
You should also get AAA (
http://www.aaa.com ) if you can, or the Canadian equivalent if it transfers to the US. If you haven't heard of it, you get as many free maps/books of campground/hotel recommendations as you want, discounts of hotels and stuff, and roadside assistance (including towing and lockouts!) It's relatively cheap, and 100% worth it.
Here are a bunch of Washington hikes:
http://www.wta.org/This probably goes without saying, but make sure you have the appropriate car/hiking emergency kits, and lots of water.
And don't go anywhere you aren't certain your car can return from!
In terms of weather, it's only going to get warmer as you go south. Western Washington/Oregon will be warmish. Eastern Washington/Oregon/California will be hot. Since you'll be travelling by car, you'll adapt fairly well, however. I recommend bringing a Nalgene, filling it up every time you stop for gas, and then just sipping on it as you drive.
I'm kind of afraid of grizzly bears and poisonous snakes too. (And cougars and poisonous spiders as well.) They're all handle-able, as long as you keep your wits about you. Really, wildlife is more scared of you than you are of it, and so you don't want to surprise it. They don't actually want to eat you, they just feel threatened. (Notable exception: cougars.) I've never actually encountered a bear/cougar, but I have encountered rattlesnakes and poisonous spiders.
Bears: To avoid bears, it's best to talk or sing while hiking, or put a bell on. (My sister likes to play the harmonica.) If you do surprise a bear, it's best to back away slowly in a non-threatening fashion. Don't make eye contact. Accounts differ on what you should do if it attacks - personally, I'd opt for playing dead with grizzlies, and fighting back with black bears, but it's really a personal choice. You can get bear-strength pepper spray. Never, ever get between a mum bear and her baby bears. Don't try to outrun them or climb trees - that's just pointless.
Cougars: Same advice re: talking while hiking. However, if a cougar threatens you, you want to yell and make yourself look bigger by holding up a jacket or your pack. Stare that sucker down like it were a common house-cat. If it attacks, you want to fight back hardcore, because playing dead doesn't work.
Spiders: Don't leave your tent door open. Shake your boots out before you put them on. I like to turn my sleeping bag out as well. Knock down spider webs with a stick when walking through the forest. Shake out jackets and stuff before putting them on.
Snakes: The main poisonous ones out here are rattlesnakes. They make a distinctive noise before they strike, so you can get out of the way. (Youtube "rattlesnake" for the sound.) It takes them awhile to recharge their venom, so they don't really want to have to strike you. Bigger ones are older (a rough estimate is the longer the rattle, the older it is,) and their venom is supposed to be weaker than that of young snakes. Wearing stout boots and long pants makes it tough for them to get a grab on you. Their striking distance is about 2/3 to an entire one of their body lengths. If you get bit, you should NOT attempt to slice open, suck out the venom, or tourniquet the area - instead, keep the injury below the level of your heart, keep your heart rate down, and seek immediate medical attention.
In terms of specific locations, I recommend the following:
Washington:
Mt. Baker / Bellingham (Bellingham is a great little college town. I've never been to Mt. Baker, but I hear there's great hiking.)
Mt. Rainier (Paradise, specifically - beautiful flowers in spring, great sledding in winter. Good hiking.)
Mt. St. Helens (Witness recent excessive volcanism & the rebirth of the landscape. Also: Ape Cave, the longest lava cave in the continental US. Also great hiking. Basically incredible, I really can't recommend it enough.)
Olympic National Park (Fantastic coast hiking, awesome rainforest hiking, large mountains.)
Grand Coulee (massive lava flows cut by um, massively by giant floods after the last ice age. Great hiking.)
Yakima and Walla Walla both have really awesome wineries to tour.
Seattle (Space Needle, waterfront, the Burke Museum, Pike Place Market, so much more.)
Olympia (hippies & hipsters at their 2nd finest. Cute shops, walkable, cheap. Nice hikes nearby.)
Oregon:
Portland (hippies & hipsters at their 1st finest. Powells City of Books, Voodoo Doughnut.)
Columbia River Gorge (massive lava flows cut through by the Columbia River. I hear they have good wineries and hikes.)
Eugene (more hippies & hipsters. Lovely little city, very granola.)
Cottage Grove, OR (fantastic covered bridges. Good for a Sunday drive.)
Oregon Caves National Monument (Awesome cave tours from March - Sept. Great milkshakes at the historic hotel. Not that far from I-5 or the coast highway, and the rangers are nice & knowledgeable, and the cave is fantastic. I highly recommend it. Good hiking nearby. Cheap USFS campground nearby.)
Redwoods National Something (Huuuuge redwood trees. Just awe-inspiring. Hiking.)
Crescent City, CA (Nice beaches. Local fav for seafood is the Chart Room.)
I've heard great stuff about Bandon, Or. and the sea lion caves, but have never been.
Ashland, Or. has a Shakespeare festival in the summertime, and is Shakespeare themed.
Crater Lake National Monument (hiking, fantastic views, giant volcano. It's totally worth the extra money for the boat ride, especially if you take an early one that drops you off on the island.)
Newberry Crater Volcanic Monument (Lovely lake that you can camp next to. Fishing, canoeing, hiking all over a large volcanic field with a variety of attractions. Also near Bend, Or., home of Deschutes Brewing Co.)
Fort Rock (Sweet ring of volcanic rocks erupted into water. Very nifty.)
John Day National Monument (The Painted Hills portion has gorgeous colored hills.)
California:
Lava Beds National Monument (Awesome lava caves! Super cool surface features as well.)
Yosemite National Park (Gorgeous, but staying there gets pricey very quickly, and the extensive bear precautions make life difficult. I hear it has great hiking, however.)
Kings Canyon/Sequoia National Monuments (Sequoia has huge trees. Kings Canyon has great glacially carved landscapes. I'm sure there's hiking.)
San Francisco (hiking at Golden Gate bridge, I think... Also heard good things about the Point Reyes Natl Seashore and Muir Woods.)
Joshua Tree (One of my favorites! Crazy desert vegetation, sculpted granite. Rock climbing haven. Also hiking, I'm sure.)
Arizona:
Death Valley National Park (Never been, heard it's incredible. Lots of hiking, but very hot!!!)
The Grand Canyon!!! (An absolute must-see. Lots of camping. Epic hiking.)
Organ Pipe Cactus National Monument (I've always wanted to go.)
Meteor Crater (Giant meteor impact crater! Used by NASA astronauts for practice.)
Sunset Crater National Monument (nice rosy volcano! Very lovely.)
Flagstaff (Cute college town. At elevation, so cooler than surrounding Arizona.)
Phoenix (Papago Butte and Pueblo Grande museum.)
If you have any questions, want more info about (most) of the above, or need suggestions for Idaho, New Mexico, or other Western states, or want other advice re: road-tripping, hiking, budget camping, or safety, feel free to post here or PM me!
