Florence, CO to Boulder, CO is 137 miles and takes about 2h 48m via Ronald Reagan Highway and CO 115, with a fuel budget near $21 and enough daylight to finish in a day. This drive connects two locations within the Mountain West region, offering a generally mixed driving experience. You'll encounter a significant portion on highways, but also have stretches on surface roads. It's a straightforward trip that can easily be completed in a single day, making it a convenient option if you're looking for a direct route between these Colorado points.
Trip Pace
Same-day drive is realistic
A same-day return is realistic if you keep stops short.
Break Rhythm
1 planned break
A short stop every 2 to 3 hours is enough for this drive.
Midpoint
68.5 miles from Florence, CO
A natural place for your longest stop of the day
, about 1h 28m into the drive
.
Main Roads
Road
Distance
Duration
Ronald Reagan Highway
68.6 mi
1h 16m
CO 115
33.2 mi
45m
Denver–Boulder Turnpike
19.8 mi
23m
Monument Valley Freeway
7.7 mi
8m
West Main Street
5.3 mi
9m
28th Street
0.8 mi
1m
Arapahoe Avenue
0.6 mi
1m
19th Street
<0.1 mi
<1m
Longest stretch:
Ronald Reagan Highway
— 68.6 mi, about 1h 16m
Turn-by-Turn Driving Directions
Step-by-step road directions between Florence, CO and Boulder, CO.
1
Start on CO 115
5.3 mi·9 min·West Main Street
2
Enter roundabout onto CO 115
121 ft·2 sec·CO 115
3
Continue on CO 115
0.7 mi·1 min·CO 115
4
Continue on CO 115
32 mi·43 min·CO 115
Use the straight lane.
5
Turn left
0.1 mi·14 sec
Toward I 25 North, US 24 West: DenverUse the left lane.
6
Take the ramp
0.3 mi·35 sec
Toward I 25 North, US 24 West: DenverUse the straight / right lanes.
7
Merge onto I 25; US 24
7.7 mi·8 min·Monument Valley Freeway
Use the straight / slight right lanes.
8
Continue on I 25
69 mi·1 hr 16 min·Ronald Reagan Highway
Use the straight / slight right lanes.
9
Take the exit
0.6 mi·51 sec
Exit 217AToward US 36 West: Westminster, BoulderUse the slight left lane.
10
Merge onto US 36
2.1 mi·2 min·Denver–Boulder Turnpike
11
Keep slight right at fork onto US 36
1.7 mi·1 min·Denver–Boulder Turnpike
12
Keep slight right at fork onto US 36
2.3 mi·2 min·Denver–Boulder Turnpike
13
Keep slight right at fork onto US 36
1.9 mi·2 min·Denver–Boulder Turnpike
Use the straight / slight right lanes.
14
Keep slight right at fork onto US 36
2.1 mi·2 min·Denver–Boulder Turnpike
Use the straight / slight right lanes.
15
Keep slight right at fork onto US 36
2.9 mi·3 min·Denver–Boulder Turnpike
Use the straight / slight right lanes.
16
Keep slight right at fork onto US 36
2.4 mi·2 min·Denver–Boulder Turnpike
Use the straight / slight right lanes.
17
Keep slight right at fork onto US 36
2.2 mi·2 min·Denver–Boulder Turnpike
18
Keep slight left at fork onto US 36
2.3 mi·2 min·Denver–Boulder Turnpike
Use the straight lane.
19
Continue on US 36
0.8 mi·1 min·28th Street
Use the left / straight lanes.
20
Turn left onto Arapahoe Avenue
0.6 mi·1 min·Arapahoe Avenue
Use the left lane.
21
Turn right onto 19th Street
143 ft·11 sec·19th Street
Use the straight / right lanes.
22
Turn left
87 ft·4 sec
23
Arrive at destination
Trip Plan
Given the relatively short duration of under 3 hours, this trip is ideal for a single-day excursion. You can easily depart in the morning and arrive in Boulder with plenty of time to spare. With only one recommended stop and a fuel cost estimated at $21, planning is minimal. Consider leaving Florence mid-morning to avoid any potential rush hour impacts as you approach the Denver metropolitan area. The flexibility of a short drive like this means you can adjust your departure time based on your preferences.
Morning Departure
Leave by 9 AM and you'll arrive before lunch.
Evening Departure
Even a 4 PM departure gets you there before dark in summer.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 68.5 miles from Florence, CO, or about 1h 28m into the drive.
The longest continuous stretch on this route runs about 68.6 miles.
This is a comfortable same-day trip.
Departure
Before you leave
Start with fuel, water, and navigation already sorted so the first hour feels easy.
First stop
Around 30 miles or 43m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 68.5 miles or 1h 28m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 2h 17m
Traffic, exits, and arrival timing usually matter more near Boulder, CO than in the middle of the route.
Before You Leave
+
Open the route before leaving Florence, CO so your first major turns are already loaded.
+
Leave with enough water and a charging cable within reach, not packed away.
+
Check your fuel range against the first long segment, especially if you are starting outside city service areas.
Day 1
Settle into the route from Florence, CO
This is one driving day of about 137 miles and 2h 48m.
Your first comfortable stop window is around 30 miles from Florence, CO.
This route can stay practical as a one-day drive if traffic stays reasonable.
Plan about 1 real break rather than only quick fuel stops.
The longest stretch is on Ronald Reagan Highway for about 68.6 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Place data sourced from public business listings. Hours and availability may vary.
Heads-up: tricky spots
5 of 17
5 decision points cluster between mile 38.5 and 123.7 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
7
38.5 mi into trip|~54m in
Turn left toward I 25 North, US 24 West: Denver
Lane positioning matters here. Multiple destination signs - pick the right one
Use the left lane.
Toward I 25 North, US 24 West: Denver
7
38.6 mi into trip|~55m in
Take the ramp toward I 25 North, US 24 West: Denver
Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / right lanes.
Toward I 25 North, US 24 West: Denver
8
115.2 mi into trip|~2h 20m in
Take the exit toward US 36 West: Westminster, Boulder
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight left lane.
Exit 217A
Toward US 36 West: Westminster, Boulder
6
121.8 mi into trip|~2h 28m in|US 36 / Denver–Boulder Turnpike
Keep slight right at fork onto US 36 / Denver–Boulder Turnpike
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
6
123.7 mi into trip|~2h 30m in|US 36 / Denver–Boulder Turnpike
Keep slight right at fork onto US 36 / Denver–Boulder Turnpike
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
Fuel & Cost
Regular Gas
$20.64 one way
$41.28 round trip
$3.83/gal25.4 MPG avg48 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.05
$21.86
$43.71
premium
$4.39
$23.70
$47.40
diesel
$5.61
$30.25
$60.50
Estimated Tolls: $1.38
Denver–Boulder Turnpike
(19.8 mi)$1.38
Toll estimates based on average 2024-2025 rates. EZ-Pass/SunPass discounts may lower the actual cost.
Estimated Trip Cost (one way, 1 person)
Fuel
$21
Tolls
$1
Meals
$25–$50
Total
$47–$72
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 47.9 kg one way.
Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $14 in charging
· 0 stops
· 67% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
41.1
0
$14.39
$6.58
Efficient EV
34.3
0
$11.99
$5.48
EV Truck/SUV
54.8
0
$19.18
$8.77
Gas CO2
48 kg
EV CO2
16 kg (67% less)
This trip is well within single-charge range for most EVs. No charging stops needed if you start fully charged.
DC fast charging avg $0.35/kWh. Home charging avg $0.16/kWh. US grid CO2: 0.39 kg/kWh.
Travel Intel
Current conditions at both ends of the drive.
Forecast as of Apr 15, 2026
Origin
Florence, CO
Late night
in Florence on Sunday
Local time
1:48 AM
MDT
Current temp
47°F
Unavailable
Live forecast
Destination
Boulder, CO
Late night
in Boulder on Sunday
Local time
1:48 AM
MDT
Current temp
72°F
Unavailable
Live forecast
Seasonal Notes
Summer travel usually means heavier construction, hotter rest stops, and busier weekend traffic around major cities.
Winter travel shortens daylight, so a route that looks manageable on paper can feel much longer after dark.
Holiday weekends tend to make both departure and arrival windows slower than the raw route time suggests.
Time zone
Same local time
Origin and destination are on the same clock, so arrival timing is easier to judge at a glance.
Temperature spread
25 degrees warmer at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
2h 48m on the road
Use the two city cards together: check the sky where you start, then compare it with the local time and temperature at arrival.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
National Parks Near This Route
Worth a detour if your schedule allows.
Florissant Fossil Beds National Monument
National Monument
Beneath a grassy mountain valley in central Colorado lies one of the richest and most diverse fossil deposits in the world. Petrified redwood stumps up to 14 feet wide and thousands of detailed fossil...
24 mi from route
~61 min detour
$10
near mile 42.5
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This route features a highway share of 44%, meaning you'll spend less than half of your travel time on high-speed roads. The longest continuous stretch on a single road is 68.6 miles on Ronald Reagan Highway. After this, you'll transition to other routes like CO 115 and the Denver–Boulder Turnpike, which will likely feel more like surface road driving with more frequent intersections and potentially slower speeds. Expect periods of both cruising and more varied road conditions.
44% highway, the rest on surface roads — varied driving throughout.
23 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 68.6 mi on Ronald Reagan Highway.
How Hard Is This Drive?
9/10
This route mixes highway mileage with some local-road sections near the start or finish. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 38.5 miles in.
Driving Effort9/10
High effort - long or complex enough to need steady focus all day
Balances navigation complexity with total wheel time.
This is a demanding drive. With 17 significant decision points across 137 miles, you will need to stay alert - especially through interchange areas and urban stretches. Consider splitting it into segments if you are not comfortable with fast highway navigation.
Where does it get tricky?
The main spots that need attention: at 38.5 miles: Lane positioning matters here. Multiple destination signs - pick the right one; at 38.6 miles: Lane positioning matters here. Multiple destination signs - pick the right one; at 115.2 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 2h 48m. Total distance: 137 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
2h 48m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (44%). Some complex stretches to watch for.
Scenic Drive
Mixed highway & surface route profile with national parks nearby.
Frequently Asked Questions
The longest stretch is about 68.6 miles on Ronald Reagan Highway. The full list of main roads is in the Roads section above.
Expect about $1.38 in tolls one way, starting with Denver–Boulder Turnpike. Most Northeast and Midwest toll agencies accept E-ZPass; in the West and Texas, transponders like TxTag or FasTrak apply. If you do not have a transponder, cashless tolling plates will mail a bill to the vehicle's registered address — usually with a surcharge, so a rental-car toll pass is often cheaper than paying by mail.
It helps. This route has a higher-than-average number of complex decision points, which get harder in the dark. If the last hour of the trip is on surface roads or mountain grades, aim to arrive at Boulder, CO before sunset when you can. Check the Trip Plan for departure windows that land you in daylight.
Only with planning. This is a long drive for kids — consider splitting it into two days rather than pushing through. Plan at least 1 meaningful breaks. Dedicated rest areas are limited, so plan gas or food stops as your bathroom breaks.
The main spots that need attention: at 38.5 miles: Lane positioning matters here. Multiple destination signs - pick the right one; at 38.6 miles: Lane positioning matters here. Multiple destination signs - pick the right one; at 115.2 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Yes — Florissant Fossil Beds National Monument. See the National Parks section for detour distances and tips on detours.
Yes. A round trip is manageable in a single day if you plan a break at Boulder, CO before heading back.
