Our family is spending four nights in RMNP and would like to spend our remaining three nights in the mountains (maybe Vail or Steamboat). We are looking to do some biking and hiking. Let me know if you have a favorite summertime ski town to visit.

thanks.

From RMNP you can easily drive over Trail Ridge Road (which is a must-do when you're at RMNP, IMHO), then into Grand Lake. With just three nights, I'd suggest you stay at Grand Lake itself. It's a gorgeous natural mountain lake, and connects to two other lakes (Shadow Mountain and Granby). If you enjoy boating, it's fun to rent a boat for a few hours and tool around on the lake(s). There are also ample opportunities for hiking and biking near Grand Lake.
If you must visit a ski area (but why in August?), Winter Park would be on your way back to Denver. It hosts a few mountain bike events every summer. The ski area has an alpine slide in the summer, too.
Steamboat would be a drive further north of almost two hours, and away from Denver (assuming you are leaving from Denver). It's beautiful, but I personally would stay in Grand Lake or Winter Park since they are beautiful, too. Spend less time in the car and more time on the trails, is my approach.
Vail would be out of your way, also, and I don't think it would add much to the other choices above, except maybe very expensive shopping.

Well, I live in Keystone, so obviously it would be my favorite. There are a ton of things to do here in summer. It's my favorite time of year. You can take your bike up the chairlift and ride back down on some great trails of all skill levels. There are also miles and miles of paved bike paths in Keystone and Summit County. You can also go boating on Lake Dillon, rent kayaks or canoes in Frisco and explore all the little coves and islands in the lake. Horseback riding out of the Keystone stables and a host of great restaurants are just two more attractions. Check the resort website to see if there might be a festival of some sort on your dates.

And Keystone is an easy drive from RMNP. Do the Trail Ridge Road through the Park and head south on the road that goes along the Blue River to Silverthorne and on to Keystone. If you are into trout fishing, the Blue is trophy water.

Also, you are only an hour and a half from Denver at Keystone.

I am at Keystone too. Why go to a resort in summer?, TONS of reasons! In August there will be lots to do. At times it seems busier than in winter. They typically have something going on each weekend. I think the wine and Jazz festival is in August. Plus the rates are very low. You can easily find a 2 bedroom condo for under 100.00 a night. http://denver.craigslist.org/vac/ often has good rates from owners.

Great biking on paved paths and off road. There is also a great hike a the top of the mountain 7-11 that you can take the ski lift up and down if your kids are young. You get the views without allot of altitude climbing. Keystone has two wonderful golf courses if you like that sort of thing.

At Lake Dillon on Sat nights there are free concerts, Great fun very family friendly. As others have said renting a pontoon boat on Lake Dillon makes for a memorable experience, again the views are breath taking. There is a restaurant that is open for lunch in summer only on Lake Dillon at the Dillon Marina, the Tiki Bar, my personal favorite lunch place.

I like Vail as well, though more pricey than Keystone, better food in Vail, but for hiking and biking I prefer Summit County. If your into Mtn Biking let me know I can recommend trails for the experienced rider.

We stayed a few days in Copper Mountain and played some golf in the area. We ended up at Breckenridge Ski resort and mountained biked down the mountain. You rent the bikes -- they make you put a credit card deposit on the bikes (1,500.00) -- the bikes have hydraulic brakes -- they hook them on the ski lift and up you go. They provide helmets -- my shoulders were sore but it is a wonderful ride down.

We like Breckenridge.

Telluride! Depending on your weekend, it could be a jazz festival or wild mushroom festival, but the hiking trails are amazing.

I have spent the last three summers in Vail and love it. For biking I like to stick to Vail Mountain. I prefer hiking trails off the main mountain. It's so nice to hike for 3-6 hours and really get to "soak in" all nature has to offer without litter and kids having silly string fights on the trail. The Vail Daily is free and will have ads for some really well priced meals throughout the week. Minturn (10 minutes away) and Vail both have markets on Saturday and Sunday, respectively, that are a fun way to kill some time.

Getting around in the summer is also easy as the buses and parking structures are both free.

Vail gets a rap for being sooooo expensive, but with some planning it can be reasonable. This is especially true in the summer when there are so many options that cost nothing, which includes free concerts through most of the summer.

I could on all day long, but if you end up going to Vail feel free to e-mail me or post on the forum. I would be more than happy to reccomend some trails and meal deals. My e-mail is [email protected]. Have fun!!!!!!!