Google Maps now offers directions by bike!
http://maps.google.com/maps?hl=en&tab=wl
Type in this address for the National Western Complex:
4655 Humboldt St, Denver, Colorado 80216
BikeDenver recommended route:
Get to the confluence of Cherry Creek and the South Platte, find your way onto either side of the river path going North. Within a mile of the confluence you will find several ways to get over to the East side of the River where the path continues on North. At around 2 miles from the confluence, just past a steep ramp up to 38th Street, you will see a sign on your left "Globeville Landing Park", next to the Pepsi building. Take the path to Arkins Ct. and turn left in front of the Pepsi building - sign on building says "Rocky Mountain Refurb" between Pepsi logos. You will soon see the Coliseum; follow the road you are on around the parking to 44th Ave, the street around the Coliseum parking lot will have changed to McFarland. Turn left on 44th, in front of the Coliseum and go under I-70 to the National Western Complex.
BikeDenver will valet park your bikes for free.