Consider combining 3 days to the Kenai with 3 days to Denali
The following is a trip Sally and I have taken several times and every visitor we’ve sent raves about it. 
It’s a “see it all in 7 days” trip you can do by car or motorhome. 

Day 1: It assumes you love driving, love mountains and have read (or will read) Robert Service poems or a  Jack London novel.  Drive east out of Anchorage on the Glenn Highway.  You go through the Matanuska Valley and in about 4 hours arrive in Glennallen.  Head north towards Tok on the “Tok cutoff” (we don’t use Route #’s in Alaska because the only routes we have are routes 1, 2 and 3).  Find a lodge, B&B or Roadhouse in your book to stay overnight before you get to Tok. 

Day 2: Drive through Tok http://www.tokalaska.com/  (I had the Texaco station there in Chapter 13 three times and then it burned down conspicuously).  A few miles north of Tok on the Alcan Highway there is a turnoff to the Taylor Highway (also known as the “Top of the World Highway”).  This is gold country.  The road literally runs on the crest of the mountains to gold mining communities of Chicken (the gold miners wanted to name it Ptarmigan, after the bird, but no one could spell Ptarmigan so they called it Chicken, which is what you call a baby Ptarmigan).  The café in Chicken has outstanding homemade pies.  Chicken is on the “40 mile River” where Jack London’s cabin was.  You’ll also see one of the last gold dredges sitting along the road.  You are only about 100 miles south of the Arctic Circle.  Further up the road is another gold mining community of sorts named Boundary.  Just past Boundary is the northernmost border crossing into Canada.  This road is only open from Memorial Day to Labor Day, as is the customs office.  You are now in Yukon Territory, Canada, (YIKES, bring a passport or you won’t get in!) and after about 2 more hours of scenic driving you will arrive at the mighty Yukon River.  There is a wonderful campground on the river just before you get to the ferry.  The ferry crosses on the half hour to Dawson City, home of the stampede of Gold Rushers in 1898.  Stop first at the visitor center and get fully briefed.  www.dawsoncity.org  .  There is a Westmark eHotel there that you will need to book in advance, but I recommend the White Ram or one of the other B&B’s in town.  We are not B&B people, generally, but the hotel options are limited and the Westmark is full of cruise ship people on bus tours.  This is the home of Robert Service and a walk up to his cabin and listen to the docent recite the poem “The Cremation of Sam McGhee” and others will get you into “The Spirit of the Yukon”.  Evening entertainment is at the  “Diamond-tooth Gertie Saloon”.  It is actually the same saloon that was there during the Gold Rush with can-can dancing and gambling (the old fashioned way).  Don’t feel guilty about losing because it is a government operated operation and all the profits go to restore and maintain the historical buildings in Dawson City

Day 3: After a great breakfast at  “Klondike Kate’s” drive 12 miles up into the old gold fields to Bonanza Creek (you won’t believe where the first strike was) and see a restored gold dredge sitting where it was last operated.  Take the tour.  Head south after lunch on the road to Whitehorse, Yukon Territory.  Its about a 5 hour drive on a nice paved 2-lane highway that parallels the Yukon River.  Tour the old River Boat on blocks at the visitor center www.city.whitehorse.yk.ca .  Stay over night at the Westmark Hotel.  Walk along the trail at the Yukon River.........1200 miles from the mouth.  Or drive on down the road to Skagwa

Day 4: Drive south about 2 hours to Skagway, Alaska  www.skagway.com .  You’ll have to cross the border back into Alaska.  Remember the “Chilkoot Trail” where the miners had to pack their gear straight up the mountain?  This is it.  Outstanding history, you’ll wonder just how they did it.  Take the half-day railroad trip on the White Pass Railroad.  Visit the visitor center and stroll the streets.  Find out where the first women’s college was in Alaska (was only open 1 year) and walk about 4 blocks to it.  Just inside the door is a hand sewn  quilt out of duck skins made by a Swedish Covenant missionary whose son, Elmer Rasmusson, later founded the National Bank of Alaska.  On his 90th birthday he donated $90 million to the Anchorage Museum of Art.  Upon his death about 5 years ago the family had to sell out to Wells Fargo to pay the estate taxes.  The bulk of the estate is a foundation supporting many good causes in Alaska.  Stay overnight at the Westmark or a B&B but book far in advance, not many options

Day 5: You have to drive back up to Whitehorse to get to the Alaska-Canadian Highway towards Anchorage.  This is the highway you’ve always heard about. You can make it in about 10 hours from Whitehorse.   There will be various terrain, etc. on this 2-lane road.  Careful of the ice-heaves.  If you need to rush back to Anchorage you can, but if you have an extra day take the cutoff at Glenallen, south to Valdez (terminus of the Alaska Pipeline).  If you are tired of Westmarks by now you should try the Aspen Hotel in Valdez www.valdezalaska.org/ .  Go to the ferry terminal and book yourself and vehicle on the next morning’s ferry from Valdez to Whittier across Prince William Sound.   If you don’t want to risk a sellout, you can buy your ticket online before you leave home on the Alaska Marine Highway web site www.dot.state.ak.us/amhs/ , or once you know your schedule give them a call a day or two in advance.  The drive over Thompson Pass and down the mountain to Valdez is even more spectacular than the drive into Skagway.

Day 6: After several days of driving you’ll enjoy sitting on the State Ferry and watching for whales, puffin, porpoise and other marine life.  You’ll pass the great Columbia glacier with ice fields and snow-capped mountains behind.  It will be the peak of the silver salmon season so you are likely to see commercial fishing boats (seiners and trollers) in operation.  You’ll get in to Whittier late afternoon and you are only about an hour or so from Anchorage.

WANT TO GO FISHING?  Alaska has lots of fish.  www.alaskanfishing.com   The problem is getting access because we have a limited road system and the roads don’t always lead to fishing.  Options are endless so it is difficult in this context to cover it all, but here is a stab at it: (get your fishing license or any needed gear at the Army/Navy store on 4th Avenue, downtown Anchorage)

Fly fishing.  You can take a fly-in guided trip for a day out of Anchorage, or go to a lodge for a week.  My oldest son was a fly fishing guide out in the Bristol Bay area for 3 summers during his college years.  He is a purist.  You can spend anywhere from $2,000 to $10,000 for a week in accommodations ranging from tents with a camp cook to a lodge with pastry chefs.  If you are a serious fly fishing person, email my son at comptopher@gmail.com and he will talk fly-fishing as much as you can handle. For fly-in fishing trips for a day or more out of Anchorage I would recommend Rust’s http://www.flyrusts.com/ .  I am working on an NABT discount there as well.  Look at the web site to appreciate how wonderful a day with them could be.  They also have bear viewing trips out of Anchorage.

Salmon fishing.  My second son loves fishing as well, but he was the one that filled the freezer for the winter.  Silver salmon will be running in late August and run 10-15 pounds.  Their fight is second to a steelhead.  You can fish in Ship Creek, just down the hill from the Hilton, or you can do a drift boat charter down the Kenai River out of Cooper Landing.  You can go on your own to various sites along the Kenai River, on the beach in Whittier or Seward, or you can take a charter out of the same places that will provide all the gear and a bait boy.  Valdez is also a great place for silvers but a further drive.  If you like to do your own thing, Millers Landing http://www.millerslandingak.com/ in Seward has Lund aluminum skiffs that you can rent and troll the shores away from the beaches.

Halibut.  Like getting out on the salt water?  Want to catch a 300 pound fish?  Charters go out of Whittier, Seward, Homer, Anchor Point or Valdez.  Don’t get on a boat that takes more than 6 people unless you want a social event.  Most halibut charters leave at 6-7 am and return around 3 unless they limit earlier.  No guarantee of a fish but you should get your limit of 2, but you could come in with 200 pounds of fish.  Even your neighbors will get sick of your halibut!!!! In any event, the boat trip and the scenery is worth the cost.   If you go to Seward, book with the Fish House .  Don’t do a half day trip.  You won’t get out of the bay to where the real halibut and ling cod are.