Used GMC Sierra 1500 AT4 for Sale nearLongmont, CO
311 vehicles found
Shop with transparent pricing.
Only show listings that include dealer fees- Year:
- 2021
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 355 hp 5.3L V8
- Combined gas mileage:
- 18 MPG
- Fuel type:
- Gasoline
- Transmission:
- Automatic
- Mileage:
- 47,146
- Stock #:
- 215801
- VIN:
- 1GTP9EED2MZ215801
Sponsored by Sterling Autoplex
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
47,146 mi
Frederick, CO
7 mi away
Good Deal
$39,995
- Year:
- 2023
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Onyx Black
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 45,933
- Stock #:
- DP13887
- VIN:
- 1GTUUEEL8PZ148649
Sponsored Listing
2023 GMC Sierra 1500
AT4 Crew Cab 4WD
45,933 mi
Denver, CO
37 mi away
Fair Deal
$50,697
- Year:
- 2019
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 355 hp 5.3L V8
- Exterior color:
- Blue
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Black
- Transmission:
- Automatic
- Mileage:
- 82,350
- Stock #:
- KZ339968
- VIN:
- 1GTP9EED4KZ339968
Sponsored Listing
2019 GMC Sierra 1500
AT4 Crew Cab 4WD
82,350 mi
Englewood, CO
41 mi away
Good Deal
$32,598
- Year:
- 2021
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 355 hp 5.3L V8
- Exterior color:
- Onyx Black
- Combined gas mileage:
- 18 MPG
- Fuel type:
- Gasoline
- Interior color:
- 4Sb--Leather, Jet Black / Kalahari, Interior Trim
- Transmission:
- Automatic
- Mileage:
- 96,055
- Stock #:
- AMZ450078
- VIN:
- 1GTP9EED7MZ450078
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
96,055 mi
Aurora, CO
33 mi away
Fair Deal
$35,690
- Year:
- 2021
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 355 hp 5.3L V8
- Exterior color:
- Onyx Black
- Combined gas mileage:
- 18 MPG
- Fuel type:
- Gasoline
- Interior color:
- 4Sb--Leather, Jet Black / Kalahari, Interior Trim
- Transmission:
- Automatic
- Mileage:
- 39,117
- Stock #:
- AMZ294011
- VIN:
- 1GTP9EED5MZ294011
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
39,117 mi
Aurora, CO
33 mi away
Fair Deal
$43,690
- Year:
- 2020
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Onyx Black
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 123,814
- Stock #:
- SP8658
- VIN:
- 3GTP9EEL0LG414061
New arrival
2020 GMC Sierra 1500
AT4 Crew Cab 4WD
123,814 mi
Thornton, CO
20 mi away
Good Deal
$31,582
- Year:
- 2022
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 277 hp 3L I6 Diesel
- Exterior color:
- White
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 30,482
- Stock #:
- TNG652545
- VIN:
- 3GTUUEET0NG652545
2022 GMC Sierra 1500
AT4 Crew Cab 4WD
30,482 mi
Highlands Ranch, CO
42 mi away
Fair Deal
$48,581
- Year:
- 2024
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Red
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 24,913
- Stock #:
- ARZ138555
- VIN:
- 1GTUUEEL0RZ138555
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
24,913 mi
Highlands Ranch, CO
42 mi away
Fair Deal
$54,332
- Year:
- 2025
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Summit White
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 38,250
- Stock #:
- SP8527
- VIN:
- 1GTUUEEL0SZ312985
2025 GMC Sierra 1500
AT4 Crew Cab 4WD
38,250 mi
Thornton, CO
20 mi away
Good Deal
$52,215
- Year:
- 2024
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Gray
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 31,690
- Stock #:
- ARZ304612
- VIN:
- 1GTUUEEL6RZ304612
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
31,690 mi
Highlands Ranch, CO
42 mi away
Fair Deal
$54,579
- Year:
- 2025
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Black
- Fuel type:
- Gasoline
- Interior color:
- Black
- Transmission:
- Automatic
- Mileage:
- 25,779
- Stock #:
- TCRPSZ296554
- VIN:
- 1GTUUEEL1SZ296554
Price drop
-$2,238
2025 GMC Sierra 1500
AT4 Crew Cab 4WD
25,779 mi
Denver, CO
20 mi away
Good Deal
$54,437
$52,998
- Year:
- 2021
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 277 hp 3L I6 Diesel
- Exterior color:
- Gray (Satin Steel Metallic)
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 101,313
- Stock #:
- U1485
- VIN:
- 1GTU9EET8MZ162144
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
101,313 mi
Frederick, CO
7 mi away
Fair Deal
$34,500
- Year:
- 2021
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Gray (Satin Steel Metallic)
- Combined gas mileage:
- 16 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 111,717
- Stock #:
- MG369823
- VIN:
- 3GTP9EEL4MG369823
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
111,717 mi
Littleton, CO
39 mi away
Great Deal
$30,998
- Year:
- 2022
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 277 hp 3L I6 Diesel
- Exterior color:
- Summit White
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 79,126
- Stock #:
- 260
- VIN:
- 1GTUUEETXNZ525138
2022 GMC Sierra 1500
AT4 Crew Cab 4WD
79,126 mi
Home delivery from Puyallup, WA
Price includes $1,180 shipping
Fair Deal
$41,357
- Year:
- 2024
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Brown
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 54,932
- Stock #:
- PRZ111338
- VIN:
- 1GTUUEEL0RZ111338
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
54,932 mi
Highlands Ranch, CO
42 mi away
Fair Deal
$50,539
- Year:
- 2024
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Onyx Black
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black
- Transmission:
- Automatic
- Mileage:
- 42,507
- Stock #:
- BC22777
- VIN:
- 1GTUUEELXRZ277625
Price drop
-$1,000
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
42,507 mi
Frederick, CO
7 mi away
Good Deal
$50,594
$49,594
- Year:
- 2019
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 355 hp 5.3L V8
- Exterior color:
- Summit White
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black w/Kalahari Accents
- Transmission:
- 8-Speed Automatic
- Mileage:
- 101,675
- Stock #:
- 21766
- VIN:
- 1GTP9EED4KZ417844
2019 GMC Sierra 1500
AT4 Crew Cab 4WD
101,675 mi
Greeley, CO
25 mi away
Fair Deal
$34,400
- Year:
- 2021
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 277 hp 3L I6 Diesel
- Exterior color:
- Gray (Satin Steel Metallic)
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black
- Transmission:
- Automatic
- Mileage:
- 90,012
- Stock #:
- VC26162
- VIN:
- 1GTU9EET9MZ174397
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
90,012 mi
Home delivery from Hicksville, OH
Price includes $1,335 shipping
Good Deal
$33,990
- Year:
- 2025
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Onyx Black
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 24,363
- Stock #:
- 260481C
- VIN:
- 1GTUUEE81SZ136542
2025 GMC Sierra 1500
AT4 Crew Cab 4WD
24,363 mi
Parker, CO
34 mi away
Great Deal
$52,014
- Year:
- 2023
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Summit White
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 66,724
- Stock #:
- APG333254
- VIN:
- 3GTUUEEL1PG333254
2023 GMC Sierra 1500
AT4 Crew Cab 4WD
66,724 mi
Aurora, CO
33 mi away
Fair Deal
$48,690
- Year:
- 2023
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Deep Bronze Metallic
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black with Kalahari accents
- Transmission:
- Automatic
- Mileage:
- 36,134
- Stock #:
- U17016
- VIN:
- 1GTUUEE83PZ264207
2023 GMC Sierra 1500
AT4 Crew Cab 4WD
36,134 mi
Henderson, CO
23 mi away
Fair Deal
$52,093
- Year:
- 2025
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Onyx Black
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 8,153
- Stock #:
- P280100
- VIN:
- 3GTUUEE89SG280100
Price drop
-$3,145
2025 GMC Sierra 1500
AT4 Crew Cab 4WD
8,153 mi
Boulder, CO
12 mi away
Great Deal
$58,350
$56,100
- Year:
- 2019
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Exterior color:
- Red Quartz Tintcoat
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 34,336
- Stock #:
- KZ192069
- VIN:
- 1GTP9EEL2KZ192069
New arrival
2019 GMC Sierra 1500
AT4 Crew Cab 4WD
34,336 mi
Littleton, CO
37 mi away
Great Deal
$39,998
- Year:
- 2021
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 277 hp 3L I6 Diesel
- Exterior color:
- Gray (Satin Steel Metallic)
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 101,313
- Stock #:
- U1485
- VIN:
- 1GTU9EET8MZ162144
Sponsored Listing
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
101,313 mi
Frederick, CO
7 mi away
Fair Deal
$34,500
Overview
The GMC Sierra 1500 is a spacious and capable pickup. It is offered in a number of trims providing a wide array of creature comforts. While GMC might be more sooner associated with the chrome-clad Denali variants, the Sierra is also available in more outdoorsy trims, such as the AT4. Designed as a sort of the anti-Denali, the AT4 is designed to get muddy. It features a 2-inch lift, Rancho shocks, upgraded underbody skid plates, an Auto-Trap two-speed transfer case, and a locking rear differential. The AT4 is not without niceties, as it receives a unique black interior with Kalahari accents and a host of creature comforts. The AT4 trim was introduced with the redesigned Sierra 1500 in 2019 and has continued through the 1500’s 2022 model year update.
Key Features
- Gas V8, Duramax Turbodiesel I6
- 2-inch suspension lift w/ Rancho shocks
- Skid plates
- Heated/ventilated front seats, leather upholstery
- Touchscreen infotainment w/ Apple CarPlay, Android Auto
Pricing Details
In Crew Cab configuration, the 2023 GMC Sierra 1500 AT4 carries a $66,700 MSRP. Used examples on CarGurus range from $26,484.00 to $85,952.00 with an average price of $32,777.21. The Sierra 1500 AT4 is available with a number of options packages. The Premium Package adds a number of upgraded driver assistance features. The Technology Package adds a head-up display, bed view camera, and rear camera mirror. The AT4 Preferred Package adds a universal garage door opener, adaptive cruise control, and a power-sliding rear window with a defogger.
Specifications
Performance
Engine
6.2-liter gas V8, 3.0-liter turbodiesel I6
Transmission
Eight-speed automatic (gas), 10-speed automatic (diesel)
Drivetrain
Four-wheel drive (4WD)
Horsepower/Torque
420 hp/460 lb-ft (gas) / 277 hp/460 lb-ft (diesel)
0-60 mph
5.8 seconds
MPG
24 mpg city, 34 mpg highway, 28 combined (6AT) / 26 mpg city, 36 mpg highway, 30 combined (5MT)
Curb weight
4,816 pounds
Dimensions
wheelbase
147.53 inches
length
231.72 inches
width
81.24 inches
height
78.35 inches
*CarGurus meticulously monitors the prices of millions of pre-owned vehicle listings, offering users precise and up-to-date market insights. Historical pricing data excludes any additional dealer fees as of May 3, 2026.
4.0 Overall rating
Filter by rating
Anonymous
Reviewed a 2019 GMC AT4 Crew Cab 4WD on Sep 9, 2024
The truck had all the features I wanted and the price was in-line, or better with others in my search.
Is this review helpful?
Buddy H
Reviewed a 2019 GMC AT4 Crew Cab 4WD on Jan 5, 2025
Slightly over priced for the miles I would pay $29000-$30000 all day
Is this review helpful?
FAQs
How much does the GMC Sierra 1500 AT4 cost in Longmont, CO?
The average GMC Sierra 1500 AT4 costs about $31,230.09. The average price has decreased by -2.9% since last year. The 311 for sale near Longmont, CO on CarGurus, range from $26,484 to $85,952 in price.
How many GMC Sierra 1500 AT4 vehicles in Longmont, CO have no reported accidents or damage?
274 out of 311 for sale near Longmont, CO have no reported accidents or damage.
What is the fuel economy of the GMC Sierra 1500 AT4?
Depending on the engine and options, the GMC Sierra 1500 AT4 gets between 15 and 24 MPG/MPGe.
What fuel types are available?
Diesel, Gasoline engines are available.
*CarGurus meticulously monitors the prices of millions of pre-owned vehicle listings, offering users precise and up-to-date market insights. Historical pricing data excludes any additional dealer fees as of May 3, 2026.
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