We got this question by email and are answering her to share with everybody:
Good Morning Frank,
I am training for BWR and i am looking for a simulation ride around Boulder Longmont. Do you have a route that you think is suitable? 120 miles TONs of climbing. Any help would be great.
Steve
Hi Steve - its all about matching the elevation profile of a route here in Colorado that comes close to the elevation profile in San Diego. The length of the climbs take care of the training from bottom to the top.
Here’s what I suggest: take the elevation profile from the BWR and see if you can use RideWithGPS.com to mimic that around here. Be creative and flexible - there is no way you’ll replicate the exact profile but you can get close. Riding 120 miles alone (actually its 133 
) takes care of most of the physiology.
Ride for 7-8 hours and that is more important that finding a route similar to the BWR. But I say that knowing there’s tons to choose from around this area - think in terms of 5 mile climbs @ 3-5% grade and avoid our long steady Canyons. Review the climbs as shown here and in the course file below.
Good luck!!