First 14er for very experienced hikers

[pleiades]

Perhaps Torreys from Grizzly, aka West Ridge?
Loveland pass is easy to drive to, parking may be a pain, but probably not too crowded once you get past the tourist spots, and definitely not busy towards Grizzly. You’d get 2 13ers, unless you do the shortcut, and at least one 14er.

[ltlFish99]

I agree with the Huron and La Plata recommendations.
I think the views from Huron are wonderful.
Another fun and beautiful hike is Yale.

[jscully205]

Surprised no one has mentioned Holy Cross. You're only a few exits away from it if you're staying in Vail. It's within your ability level if acclimatized and as fit as you probably are. By the end of Sept there could be snow on the ground at higher elevations, but if there are not any rogue storms it'll be of minor inconvenience. Would pack warm clothes and a lot of layers because it could also be a warm sunny day.

[peter303]

I suggest Quandary or Elbert. Their access roads are OK for rental cars. A thin snow/ice crust would not be troublesoome.

[arianna2]

If you have a couple days then I would suggest doing a hike just up to 12 or 13000 the first day. It helps acclimation. There are a lot of hikes in the area. Maybe Uneva peak or one of my favorites is taking the Fall Creek Trail up to the Notch Mtn shelter. Not sure there would be snow in the cross of Mt of holy cross but just a spectacular view anyway. Don't do the halo ridge, it is too long above 13000, just up to the shelter. Then if you do ok,, the next day do something like Torrey's Kelso ridge route. You will feel better doing it after a lower elevation hike. Kelso ridge would be a little more of a challenge that you might like versus the standard route. Weather is generally good in September but can be nasty so you'll have to have a plan B. Fall colors can be beautiful at the end of September too. LA Plata can be awesome with colors.

[highplaces]

Hi smbigs1, I predict you are going to LOVE Colorado! I’m a 46er (both summer and winter) and lived in Lake George, NY before moving to Colorado a decade ago. Be careful…..for us, our move here started with a week vacation to Breck to climb 14ers, then a 6 month temp living in Breck the following summer to do all the 14ers, then…..moving here. If you like mountains (and it sounds like you both do!) it’s pretty irresistible.

September is a great month, you’ll see fall leaves, most likely get great weather (so many bluebird days in Sept), though always a chance of a freak snow up high – not enough to bring snowshoes or crampons. You’ll may get some chilly overnights and starts.

When I came from NY to CO for a week to hike for the first time, I had no major issues with the altitude, I was just slower. Like most everyone says, make sure to drink lots of water, don’t go crazy with the booze (you’ll feel it more), eat frequently on your hikes and take your time.

You’ve already gotten a lot of great suggestions for 14ers. If you’re looking for something a bit quieter, I’d consider these:
-Go up either the Booth Creek or Pitkin Creek drainages out of Vail up to each respective lake. You can make a loop out of these 2 trails, or climb peaks (skiers, climbers, solitude), but both require off trail travel which I’m not sure you’re looking for.
-Out of Frisco, take Meadow Creek trail to Eccles Pass, then you can go up either Deming or Eccles mountains (or both), both are easy walk ups.
-Out of Copper, go up the Wheeler Trail to Peaks 8/7/6 and loop back down. It will be off trail between the peaks, but very straightforward and easy.
-Uneva Peak from Vail Pass

If you’re staying in Vail, I wouldn’t spend my time driving any further east than Frisco to hike. Feel free to reach out for more details, I’m happy to help with hike stats, photos, etc. Have the best time!