Hood River gets my vote: Awesome creeking and reasonable play boating within minutes of town. Good food and great beer, especially considering it's a small town. Skiing is an hour away. Best off, you can paddle year round and can ski nearly year round. The Portland airport is less than an hour away if you need a quick getaway and downtown Portland, a very fun city, is one hour from HR.
Speaking of Portland, for a medium sized city, that would be my go-to. Hood River is only an hour away and there are a bunch more runs north, south and west of town, including some really great creeks that aren't super hard core but are way fun (IV+). Surfing in the ocean is 90 minutes from downtown.
Seattle is also a great boating city (my home for the last couple of decades). Tons of runs within 60-90 minutes and tons more if you want to drive another 30. Plus Seattle is one of the all time great cities.
Not to rile up all the Coloradans (I just moved here, be kind) but you can boat 365 days a year in the NW, although you'll need a drysuit. Also, the beer, food and coffee scenes are more developed and cutting edge there than here. Oh yeah, British Columbia is only 2 hours away. Talk about creeking central...
One more little secret stash town: Medford, Oregon. There is all kinds of boating around there, within an hour or two. You're within a half day of awesome CA granite and the ocean is two hours away. The ski area, Mt. Ashland is very small but pretty fun. Two hours south there is a ton of awesome back country skiing with very few people around. That same area is home to some great rivers as well, such as the Cal Salmon drainage. Ashland is about 10 minutes away and is a pretty cool little college town. The closest city is Portland, about 4.5 hours north so don't count on an easy big city fix though.
That said, I'm excited to be boating here in CO and I'm looking forward to all the great stuff the Rockies have to offer. The key ingredient here is the sunshine! It's pretty cool to go boating and have your stuff dry before you get home. That doesn't happen in the NW, ever (except maybe Medford). The other great thing here are all the play parks. There isn't a one in Oregon or Washington.
Good luck on your quest!