Is there a bus to Boulder?

There is no direct bus service from Spearfish to Boulder.

How long is the drive?

The drive takes approximately 6 hours.

Only if you choose to use the E-470 toll road near Denver.

Yes, the drive through the Black Hills and Wyoming plains is very beautiful.

You would need to drive to Rapid City to fly to Denver, which is not faster than driving.

Spearfish

Boulder

Driving

Spearfish to Boulder

Updated: 28 May 2026

The drive from Spearfish to Boulder covers approximately 600 kilometers and takes about 6 hours via US-85 South and I-25 South. You will depart the Black Hills and descend into the high plains of Wyoming before entering the Front Range of Colorado. This route is highly scenic, passing through the Thunder Basin National Grassland. It is a straightforward drive suitable for a single-day trip.

Total Distance: 600 km driving distance; 520 km straight-line air distance.

Fastest Way

Driving is the only practical mode, taking 6 hours.

Cheapest Way

Driving your own car is the most economical and convenient option.

Compare Spearfish to Boulder Routes

Driving

Direct

Duration

6 hours

Avg Price

$80 - $120 in fuel

Operator

Personal Vehicle

Route

US-85 South to I-25 South, exiting at CO-119 for Boulder.

Use the E-470 toll road if you want to bypass Denver traffic entirely.

Travel Tips

Parking
Use the city parking garages in downtown Boulder to avoid expensive street parking fines.
Hydration
Boulder is at a high altitude; drink plenty of water to prevent headaches.
Traffic
Avoid I-25 during rush hour near Denver to save significant time.
Gear
Bring layers, as mountain weather in Colorado can change rapidly.
Navigation
Download maps for the Wyoming stretch where cell service is spotty.

Safety Tips

Speed Limits
Observe speed limits strictly in small Wyoming towns along US-85.
Mountain Driving
Use lower gears when descending steep grades into the Front Range.
Emergency Supplies
Keep a basic first aid kit and water in your car.
Weather Alerts
Check for high wind warnings on the plains before leaving.