Trail Ridge Road may be closed by then (due to snow). Maybe someone else with better knowledge can comment. I've heard it is a wonderful time to visit, but there may be snow already in higher elevations. We are going mid-September ourselves (and have been there before in the middle of summer).

You may miss the peak of the color change. Sometimes by the first of Oct it is over except at lower elevations. PPeak and the Garden were unaffected by the fires. Came close to the Garden and a good portion of the foothills north and west of C Springs are charred. Best bet for leaves could be 24 to 67 through Evergreen and finally 72/7 commonly called Peak to Peak highway. Not a very direct route but it will get your there. Peak to Peak is one of the premier drives for leaves but your time could be a little off. All depends on the weather. We have had a very dry year and means early leaf turning and quick.

Regarding accommodation in Estes, I recommend Silver Moon Inn or Deer Crest Resort.

The tour of the Stanley Hotel was mildly interesting and the trail around Bear Lake is excellent. Mary's Lake Lodge is a good place for dinner.

My husband & I have made a yearly sojourn to Estes Park for the last five years. This Oct 4-8 will be our sixth trip! The beginning of October is my FAVORITE time to go!

We were there last year from Oct 1-8 and the Aspen trees were gorgeous!! At that time Trail Ridge Road was not closed. It typically closes soon after the beginning of October because when the snow gets to be too much to plow they give in to Mother Nature. Even when it does close, it is open the first 8 miles.

Bear Lake Rd is open year round. We love the hiking trails at Bear Lake! http://www.nps.gov/romo/planyourvisit/upload/bear_lake_summer_trails.pdf
This year there are construction delays on Bear Lake Road. You can travel in your car on Bear Lake Rd but you have to make the cut off time of 9am or wait until after 4pm. If not by car then you can take the shuttle buses that are running on the road.

Every year we stay at the Fall River Cabins: http://www.fallrivercabins.com/Index.html
The cabins book quickly so I would look to see if your dates are open. We have stayed in the Bristlecone, Juniper, and Pinecone. We love all of them!

From Boulder to Estes Park, here is the map for the Peak to Peak byway: http://www.nps.gov/romo/planyourvisit/upload/bear_lake_summer_trails.pdf
According to the map you can take the 119 from/or before Boulder to Nederland then your on the byway.

While staying in Estes Park, one morning you must go eat at the Meadow Mountain Cafe in Allenspark. The google directions from the Fall River Cabins to the Meadow Mountain say 30 minutes but it didn't seem like that long. Really I would say that it took 20 minutes. It is totally worth it!! The drive is beautiful and the breakfast was absolutely delicious! The Meadow Mountain is the cutest spot for breakfast that is nestled in the mountains! http://www.yelp.com/biz/meadow-mountain-cafe-allenspark

Enjoy your time in Colorado and my favorite, Estes Park!

I pasted the Bear Lake Rd twice instead of the byway. Here is the byway link: http://byways.org/explore/byways/2114/travel.html

After an extended early morning photo op/drive up Pikes Peak - we continued on up 24 through the "middle" of the state - over the pass into Breckenridge and The Summit. It's a beautiful drive. http://tinyurl.com/dx5lt85 and if you want to visit/take a look at Vail - it's only about 20 minutes down the freeway.

And we stayed the night at our favorite little Hotel/B & B - in Frisco - appropriately enough named the Frisco Lodge. http://www.friscolodge.com/

Went across the street to an Italian place for dinner - and they had Steelhead from Oregon - my home state - and it was as good as we have ever tasted. Just marvelous.

And from Frisco - there is a "back way" up to Estes Park - so you don't have to go all the way into Denver. You'd have to look at a map - but I think it heads up toward/past Boulder - through a town that now has gambling, etc. It was also a very scenic drive.

Actually - just looked at the map again and there are two ways from The Summit area to get to Estes Park, assuming there haven't been any early storms shutting one or both down.