Millsboro
Millsboro
Boulder
Boulder
Flight Driving

Millsboro to Boulder

Updated: 29 May 2026

The distance from Millsboro to Boulder is approximately 2,700 km. Flying from Philadelphia (PHL) to Denver International Airport (DEN) and then driving 45 minutes to Boulder is the most practical method. Driving takes about 27 hours via I-80 W. Boulder is famous for its outdoor recreation and the Flatirons.

Total Distance: 2,700 km driving distance; 2,400 km straight-line air distance.
Fastest Way
Flight from PHL to DEN is the fastest at 4.5 hours.
Cheapest Way
Driving is cheaper for groups, but flying is much faster.
Compare Millsboro to Boulder Routes
Flight
Direct
Driving
Direct
Duration 4 hours 30 mins 27 hours
Avg Price $250 - $450 $350 - $550 in fuel
Operator United Airlines Personal Vehicle
Route PHL to DEN, then drive to Boulder I-80 W
Tip Direct flights to DEN are frequent and convenient. The drive is long; plan for multiple overnight stops.
Travel Tips
  • Altitude
    Boulder is at high altitude; stay hydrated.
  • Transportation
    A car is recommended for exploring the area.
  • Dining
    Try the local craft breweries and farm-to-table restaurants.
  • Weather
    Expect cool nights even in summer.
  • Booking
    Book accommodation in advance for peak season.
Safety Tips
  • Driving
    Be cautious on mountain roads.
  • Altitude
    Be aware of altitude sickness symptoms.
  • General
    Stay hydrated and use sunscreen.
  • Emergency
    Keep emergency supplies in your vehicle.
People Also Ask
  • Is Boulder safe?
    Generally safe, but stay aware of your surroundings.
  • How long is the drive?
    About 27 hours from Millsboro.
  • Are there direct flights?
    Yes, from PHL to DEN.
  • What is the best time to visit?
    Summer for hiking.
  • Is it expensive?
    It can be, but there are many free activities.
Quick Info
  • From Millsboro, Delaware, United States
  • To Boulder, Colorado, United States
  • Modes
Best Time to Travel

June to August for hiking and outdoor activities.

Things to Do in Boulder
1
Pearl Street Mall
A vibrant pedestrian mall with shops and restaurants.
2
Chautauqua Park
Offers access to hiking trails with views of the Flatirons.
3
Boulder Creek Path
A scenic path for walking and biking.
4
NCAR Trail
Great for hiking and panoramic views.
Tags
Millsboro to Boulder flights to DEN driving to Boulder Delaware to Colorado travel best way to Boulder Boulder travel guide road trip to Colorado PHL to DEN