My favorite loop is from REI in Denver down the Platte to Chatfield and up Deer Creek/High grade road. I don't know if this will come through but this is the map:
http://connect.garmin.com/activity/89312594 I wrote a detailed description for my riding group:
For those new to Denver or new to road cycling and want a detailed route description, see below:
Denver to Chatfield and Deer Creek loop
75 miles round trip
4200 feet of climbing
Start from REI.
-Travel South on the Platte trail. You'll take the trail for 20 miles
all the way to the Chatfield reservoir. If you haven't been on the
Platte trail, there are multiple places where you jog back and forth
across the river. It's a little confusing because there are also
several different trails that originate on the Platte and you could
find yourself on the wrong trail. The one place you need to know about
is right when you get to the movie theaters that will be on the right.
It's about 10 miles from Denver (I think...). You need to cross the
river here. If you continue straight you will end up on the Bear Creek
trail. You're on the correct trail if you're always going along the
river.
-When you get to Chatfield (at this point you'll be on the C-470 West
trail. It changes names near Chatfield) climb the hill that goes up
and over the reservoir. As you come down the other side where the lake
is on your left you'll see the main park road. Make your way over to
the road (the trail goes there). Once on the road continue going in
the same direction until you get to the main park entrance on your
right (couple miles). Go out the main park entrance and turn right on
Wadsworth. The first light you come to is Deer Creek Canyon. Turn left
and get ready to climb.
-From the turn onto Deer Creek you will be climbing for 14 miles. The
first few miles are a little rolling but then it turns for real. There
is one stop sign. You'll go left to continue on Deer Creek. I think
it's actually pretty well marked. Approx 6 miles from where you enter
Deer Creek you will see a road on your left that is also named Deer
Creek. Turn left here. 2.2 miles from this turn the real fun starts.
Deer Creek turns into High Grade Road. It's not just a clever name.
You'll know when you hit it because the road starts switch backing. It
is hella steep here for several miles. And if you're lucky, like
today, you'll also have a head wind. When High Grade is done it turns
into Pleasant Park Road. Unfortunately this is a clever name. It's not
pleasant. The road continues climbing for a few more miles. Just when
you think you can't pedal any more you will see the road go in between
an area with trees on both sides. This is the "top"
- ALWAYS bring cash with you on this ride. At the top of the climb
there is a "cyclist rest stop". It is stocked every single day with
cold gatorade, water, snickers bars and energy bars. There are also
porta potties. There is a box that you put donations into when you
take drinks. This is really the only place to fill up on this ride. I
always try to give extra money. We want them to keep doing this!
- Don't stop for too long because there are still a couple short steep
climbs and you don't want your legs to lock up.
- As you leave you will be descending for a little while. Keep your
eyes out because you will be turning right on Oehlmann road. I think
it's the first road that you can turn right onto. You may want to get
a little speed on this little descent because there is a short steep
hill at the bottom. But watch out because you turn left 90 degrees
when you begin climbing the hill. Stay generally on this road. It will
do some steep switchbacking and it turns into Crystal Way. More
switchbacking and you finally make your way to City View road.
- Stay on City View road. You will come upon a pretty remarkable view
of Denver. It's awesome. Stay on CityView until you hit Turkey Creek.
If you come to any forks in the road on cityview and don't know which
way to go, pick the direction that goes down. At this point your legs
won't allow you to pick the other direction anyway. As a caution,
Cityview is VERY dodgy. Very steep, many quick 180 degree turns and
ample driveways. Keep your speed in check!
-When you hit Turkey Creek, Go right (DOWN). This is where you can let
loose like you're trying to win a mountain stage in the TdF. When the
road starts to level off you'll see a fire department on your left and
a climb on your right. That's your next turn. And last big hill. It's
Deer Creek Road again. Turn right on Deer Creek.
-The hill when you turn onto Deer Creek is less than a mile. But it's
all worth it because after you finish that hill it's about 10 miles
downhill back to Wadsworth. This is a very fun descent. The road is
very well maintained, no potholes and little gravel. If you're daring
and like descents you can probably hit 50. I hit the brakes at 40
myself.
-You will see the Deer Creek turn that you took when you started.
You'll think to yourself that one day, just one day you'll do the
climb twice. And then you'll cruise right by it on your way back home.
-Backtrack your way back to the C-470/Platte trail (right on
Wadsworth, left into the park then find the bike path) and head back
to Denver.
You could also look at the route for the Denver Century ride that is happening on June 12:
http://denvercenturyride.com/...0-mile-century-ride/ Staying on the trails the whole time would be a little painful. You can connect Cherry Creek trail to C-470 to the Platte for a round trip of about 75 miles. It's not very scenic. And requires one stretch on a road to get from Cherry Creek to the 470 trail.
Have fun!
Jodi