Origin
Castlewood, CO
Late night in Castlewood on Saturday
Local time
12:14 AM
MDT
Current temp
77°F
Unavailable
Live forecast
Trip from Castlewood, CO to Longmont, CO
Compiled and reviewed by the Trip.ovh planning team at COD Solutions Oy · Last reviewed Apr 18, 2026 · Editorial standards
Drive Time
1h 7m
Distance
52.2 mi
84 km
Drive Score
7/10
Good drive
Same Day?
Yes, doable
Fuel Cost
$8
one way
EV Charging
Sparse
1 stations
Best Time to Leave
4 AM
1h 2m
★
6 AM
1h 7m
8 AM
1h 18m
10 AM
1h 11m
12 PM
1h 10m
3 PM
1h 11m
5 PM
1h 17m
8 PM
1h 4m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Castlewood, CO
Liudmyla Shalimova
Longmont, CO
Wikimedia Commons
Trip Overview
This 52.2-mile drive from Castlewood, Colorado, to Longmont, Colorado, will take you about 1 hour and 7 minutes. It's a straightforward day trip, easily completed in a single day with a modest fuel cost of around $10. The route primarily utilizes local roads and highways, offering a more connected feel to the landscape rather than a high-speed interstate journey. You'll be navigating through the Mountain West region of Colorado for the entire trip, experiencing the local flow of traffic. Given its short duration, this drive is perfect for a spontaneous outing or a relaxed start to a longer adventure.
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 1h 7m. Total distance: 52.2 miles.
Family Friendly
Moderate complexity with 0 natural rest stops along the way.
Solo Traveler
1h 7m drive, comfortable solo distance.
EV Driver
0 DC fast chargers along the route. Coverage: unknown.
Scenic Drive
Turn-heavy local drive route profile.
Drive Character
Expect a turn-heavy local drive for this 52.2-mile stretch. Only about 6% of the journey involves highway driving, meaning you'll spend most of your time on more intimate local roads. The longest uninterrupted stretch you'll encounter is 21 miles on South Valley Highway, so you'll be adjusting your speed and direction frequently. This profile suggests a drive where you'll be more engaged with the immediate surroundings, rather than a monotonous highway cruise. The road will likely feel more personal as you transition between South Valley Highway, Dwight D. Eisenhower Highway, and North Valley Highway.
This route has more turning and local-road decision points than a simple highway run.
There are about 19 navigation steps in the underlying route data, so the final approach matters more than the middle miles.
South Valley Highway is the longest continuous segment at about 21 miles.
How Hard Is This Drive?
Expect a hands-on drive with frequent turns and local roads rather than long highway stretches. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 1 miles in near CR 42 / East Arapahoe Road.
Driving Effort
9/10
Demanding - stay alert through the decision-heavy sections
Balances navigation complexity with total wheel time.
This drive requires moderate attention. Across 52.2 miles you will encounter 15 spots where lane choice or exit timing matters. Not difficult for experienced highway drivers, but worth previewing the tricky sections before you go.
Where does it get tricky?
The main spots that need attention: at 1 miles (CR 42 / East Arapahoe Road): Lane positioning matters here; at 23.2 miles (I 25 / North Valley Highway): Highway fork - watch signs carefully. Lane positioning matters here; at 27.6 miles (I 25 / North Valley Highway): Highway fork - watch signs carefully. Lane positioning matters here.
Critical Maneuvers
5 of 15 key pointsThese are the spots where you need to pay the most attention. Preview them before you drive.
6
1 mi into trip
|
~2m in
|
CR 42 / East Arapahoe Road
Turn right onto CR 42 / East Arapahoe Road
Lane positioning matters here
Use the right lane.
6
23.2 mi into trip
|
~32m in
|
I 25 / North Valley Highway
Keep slight right at fork onto I 25 / North Valley Highway
Highway fork - watch signs carefully. Lane positioning matters here
Use the slight right lane.
6
27.6 mi into trip
|
~37m in
|
I 25 / North Valley Highway
Keep slight right at fork onto I 25 / North Valley Highway
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / right lanes.
7
45.1 mi into trip
|
~55m in
Take the exit toward CO 119 West: Firestone Boulevard
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the straight / slight right lanes.
Exit 240
Toward CO 119 West: Firestone Boulevard
6
45.3 mi into trip
|
~56m in
Keep slight left at fork toward CO 119 West: Longmont
Highway fork - watch signs carefully
Toward CO 119 West: Longmont
Main Roads
| Road | Distance | Duration |
|---|---|---|
| South Valley Highway | 21 mi | 27m |
| Dwight D. Eisenhower Highway | 12.2 mi | 12m |
| North Valley Highway | 9.6 mi | 11m |
| Highway 119 | 3.1 mi | 3m |
| East 3rd Avenue | 1.9 mi | 3m |
| East Ken Pratt Boulevard | 1.6 mi | 1m |
| East Arapahoe Road | 1.1 mi | 1m |
| South Quebec Street | 0.8 mi | 1m |
Longest stretch:
South Valley Highway
— 21 mi, about 27m
Turn-by-Turn Driving Directions
Step-by-step road directions between Castlewood, CO and Longmont, CO.
1
Start on East Fremont Drive
0.1 mi
·
33 sec
·
East Fremont Drive
2
Turn right onto East Hinsdale Avenue
497 ft
·
24 sec
·
East Hinsdale Avenue
3
At end of road, turn right onto South Quebec Street
0.8 mi
·
1 min
·
South Quebec Street
4
Turn right onto CR 42
1.1 mi
·
1 min
·
East Arapahoe Road
Use the right lane.
5
Take the ramp
0.2 mi
·
23 sec
Toward I 25 North: Denver
6
Merge onto I 25
21 mi
·
27 min
·
South Valley Highway
Use the straight / slight right lanes.
7
Keep slight right at fork onto I 25
4.3 mi
·
5 min
·
North Valley Highway
Use the slight right lane.
8
Keep slight right at fork onto I 25
5.3 mi
·
5 min
·
North Valley Highway
Use the straight / right lanes.
9
Continue on I 25
12 mi
·
12 min
·
Dwight D. Eisenhower Highway
10
Take the exit
0.2 mi
·
18 sec
Exit 240
Toward CO 119 West: Firestone Boulevard
Use the straight / slight right lanes.
11
Keep slight left at fork
290 ft
·
7 sec
Toward CO 119 West: Longmont
12
Turn left onto CO 119
3.1 mi
·
3 min
·
Highway 119
Use the left / straight lanes.
13
Continue on CO 119
1.6 mi
·
1 min
·
East Ken Pratt Boulevard
14
Take the exit
226 ft
·
6 sec
15
Turn right onto East 3rd Avenue
1.9 mi
·
3 min
·
East 3rd Avenue
Use the right lane.
16
Turn right onto Kimbark Street
0.2 mi
·
55 sec
·
Kimbark Street
17
Turn left
186 ft
·
15 sec
18
Turn right
109 ft
·
7 sec
19
Arrive at destination
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Halfway Point
Midpoint
About 26.1 mi from Castlewood, CO · 36m into the drive
Mid-route town
Meal stop
26 mi into the route
Best for: Lunch, fuel, and a longer reset
This sits close to the middle of the route, so it works well for the longest stop of the day.
Pacing Suggestions
Fuel and coffee
A short stop after about 11 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 26.1 miles from Castlewood, CO, which is a good place for a longer meal and fuel stop.
Arriving in Longmont, CO
The final approach into Longmont, CO usually feels slower than the middle of the drive, so avoid planning your tightest schedule at the very end.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Fuel & Cost
Regular Gas
$7.86 one way
$15.73 round trip
$3.83/gal
25.4 MPG avg
18 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.05 | $8.33 | $16.65 |
| premium | $4.39 | $9.03 | $18.06 |
| diesel | $5.61 | $11.53 | $23.05 |
No toll roads detected on this route.
Drive Cost (one way)
Fuel
$8
Estimated CO2 emission: 18.3 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $5 in charging · 0 stops · 67% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 15.7 | 0 | $5.48 | $2.51 |
| Efficient EV | 13.1 | 0 | $4.57 | $2.09 |
| EV Truck/SUV | 20.9 | 0 | $7.31 | $3.34 |
Gas CO2
18 kg
EV CO2
6 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.
Destination
Longmont, CO
Late night in Longmont on Saturday
Local time
12:14 AM
MDT
Current temp
79°F
Unavailable
Live forecast
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
2 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
1h 7m 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.
Frequently Asked Questions
The drive from Castlewood, CO to Longmont, CO covers 52.2 miles and takes about 1h 7m without stops. Add 15-30 minutes for a fuel or rest stop on longer drives.
The main roads are South Valley Highway, Dwight D. Eisenhower Highway, North Valley Highway. Expect a mix of highway and local road driving.
This is a comfortable same-day trip.
The midpoint is about 26.1 miles from Castlewood, CO. Look for rest areas, gas stations, or food options near the halfway mark.
At current regular gas prices, expect to spend about $7.86 one way. This estimate uses 25.4 MPG — your actual cost will vary with your vehicle's fuel efficiency and current gas prices.
Leave by 9 AM and you'll arrive before lunch. Even a 4 PM departure gets you there before dark in summer.
This drive requires moderate attention. Across 52.2 miles you will encounter 15 spots where lane choice or exit timing matters. Not difficult for experienced highway drivers, but worth previewing the tricky sections before you go.
The main spots that need attention: at 1 miles (CR 42 / East Arapahoe Road): Lane positioning matters here; at 23.2 miles (I 25 / North Valley Highway): Highway fork - watch signs carefully. Lane positioning matters here; at 27.6 miles (I 25 / North Valley Highway): Highway fork - watch signs carefully. Lane positioning matters here.
The route from Castlewood, CO to Longmont, CO does not surface many named destination signs beyond the main corridor.
How this page is built
Compiled by the Trip.ovh planning team at COD Solutions Oy from open government datasets — OSRM over OpenStreetMap for geometry, and EIA for fuel prices. See our methodology for refresh cadence and limitations.
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