Used GMC Sierra 1500 AT4 for Sale nearBoulder, CO
318 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:
- 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:
- 142,945
- Stock #:
- L175203
- VIN:
- 1GTP9EEL1MZ175203
Sponsored by Mike Maroone Chevrolet Buick GMC Longmont
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
142,945 mi
Longmont, CO
16 mi away
Great Deal
$29,523
- 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
- Transmission:
- 10-Speed Automatic
- Mileage:
- 25,577
- Stock #:
- KM203964
- VIN:
- 1GTUUEE81SZ203964
Price drop
-$1,212
Sponsored Listing
2025 GMC Sierra 1500
AT4 Crew Cab 4WD
25,577 mi
Highlands Ranch, CO
35 mi away
Fair Deal
$58,736
$57,524
- Year:
- 2024
- 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:
- 25 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 72,145
- Stock #:
- RZ131496
- VIN:
- 1GTUUEE83RZ131496
Sponsored Listing
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
72,145 mi
Lone Tree, CO
37 mi away
Great Deal
$45,912
- 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:
- 142,945
- Stock #:
- L175203
- VIN:
- 1GTP9EEL1MZ175203
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
142,945 mi
Longmont, CO
16 mi away
Great Deal
$29,523
- Year:
- 2022
- 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:
- 16 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 21,582
- Stock #:
- NZ643812C
- VIN:
- 1GTPUEEL0NZ643812
Price drop
-$3,299
2022 GMC Sierra 1500
AT4 Crew Cab 4WD
21,582 mi
Castle Rock, CO
50 mi away
Great Deal
$50,598
$47,998
- 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:
- 38,318
- Stock #:
- L314451
- VIN:
- 3GTUUEEL7PG314451
New arrival
2023 GMC Sierra 1500
AT4 Crew Cab 4WD
38,318 mi
Longmont, CO
16 mi away
Good Deal
$50,998
- Year:
- 2024
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Summit White
- Combined gas mileage:
- 25 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 58,199
- Stock #:
- L221653A
- VIN:
- 1GTUUEE85RZ221653
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
58,199 mi
Longmont, CO
16 mi away
Good Deal
$48,858
- Year:
- 2024
- 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:
- 25 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 60,296
- Stock #:
- RZ162144T
- VIN:
- 1GTUUEE86RZ162144
Price drop
-$1,699
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
60,296 mi
Castle Rock, CO
50 mi away
Great Deal
$48,697
$47,697
- Year:
- 2022
- 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:
- 16 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 59,090
- Stock #:
- ANZ646375
- VIN:
- 1GTPUEEL8NZ646375
2022 GMC Sierra 1500
AT4 Crew Cab 4WD
59,090 mi
Aurora, CO
30 mi away
Fair Deal
$47,290
- Year:
- 2023
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Sterling Metallic
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 71,923
- Stock #:
- M1000E
- VIN:
- 1GTUUEE81PZ240925
2023 GMC Sierra 1500
AT4 Crew Cab 4WD
71,923 mi
Castle Rock, CO
50 mi away
Fair Deal
$44,792
- 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
30 mi away
Fair Deal
$44,946
- Year:
- 2024
- 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:
- 25 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black with Kalahari accents
- Transmission:
- Automatic
- Mileage:
- 34,011
- Stock #:
- U16925
- VIN:
- 1GTUUEE86RZ207647
Price drop
-$1,733
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
34,011 mi
Henderson, CO
22 mi away
Good Deal
$54,593
$52,860
- Year:
- 2024
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Volcanic Red Tintcoat
- Combined gas mileage:
- 25 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 62,702
- Stock #:
- ARZ215935
- VIN:
- 1GTUUEE87RZ215935
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
62,702 mi
Aurora, CO
30 mi away
Fair Deal
$50,840
- Year:
- 2020
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 420 hp 6.2L V8
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Transmission:
- Automatic
- Mileage:
- 85,005
- Stock #:
- 342666
- VIN:
- 3GTP9EEL2LG342666
2020 GMC Sierra 1500
AT4 Crew Cab 4WD
85,005 mi
Frederick, CO
17 mi away
Fair Deal
$39,133
- 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:
- 32,629
- Stock #:
- SZ143110C
- VIN:
- 1GTUUEE87SZ143110
Price drop
-$1,999
2025 GMC Sierra 1500
AT4 Crew Cab 4WD
32,629 mi
Castle Rock, CO
50 mi away
Great Deal
$53,997
$52,697
- 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:
- Onyx Black
- Combined gas mileage:
- 16 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black With Kalahari Accents, Perforated Leathe
- Transmission:
- Automatic
- Mileage:
- 98,592
- Stock #:
- PMG472190
- VIN:
- 3GTP9EEL2MG472190
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
98,592 mi
Aurora, CO
30 mi away
Fair Deal
$37,240
- 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:
- 38,200
- Stock #:
- 16571Z
- VIN:
- 1GTUUEEL1SZ329617
New arrival
2025 GMC Sierra 1500
AT4 Crew Cab 4WD
38,200 mi
Brighton, CO
23 mi away
Fair Deal
$54,988
- Year:
- 2024
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Volcanic Red Tintcoat
- Combined gas mileage:
- 25 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black With Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 23,292
- Stock #:
- TWF1774
- VIN:
- 3GTUUEE8XRG342730
New arrival
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
23,292 mi
Home delivery from Tulsa, OK
Price includes $1,152 shipping
Fair Deal
$55,612
- Year:
- 2023
- Make:
- GMC
- Model:
- Sierra 1500
- Body type:
- Pickup Truck
- Doors:
- 4 doors
- Drivetrain:
- Four-Wheel Drive
- Engine:
- 3L I6 Diesel
- Exterior color:
- Sterling Metallic
- Combined gas mileage:
- 24 MPG
- Fuel type:
- Diesel
- Interior color:
- Jet Black w/Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 96,376
- Stock #:
- 142692
- VIN:
- 1GTUUEE87PZ142692
2023 GMC Sierra 1500
AT4 Crew Cab 4WD
96,376 mi
Home delivery from Mesa, AZ
Price includes $1,150 shipping
Great Deal
$37,740
- 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:
- Black
- Combined gas mileage:
- 17 MPG
- Fuel type:
- Gasoline
- Interior color:
- Black
- Transmission:
- 8-Speed Automatic
- Mileage:
- 93,470
- Stock #:
- 170072
- VIN:
- 1GTP9EED1KZ170072
2019 GMC Sierra 1500
AT4 Crew Cab 4WD
93,470 mi
Denver, CO
23 mi away
Fair Deal
$34,995
- 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:
- 45,931
- Stock #:
- DP13887
- VIN:
- 1GTUUEEL8PZ148649
2023 GMC Sierra 1500
AT4 Crew Cab 4WD
45,931 mi
Denver, CO
28 mi away
Fair Deal
$51,198
- 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:
- [GAZ] Summit White
- Combined gas mileage:
- 16 MPG
- Fuel type:
- Gasoline
- Interior color:
- Jet Black w/Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 136,039
- Stock #:
- 281143
- VIN:
- 1GTP9EEL2MZ281143
![[GAZ] Summit White 2021 GMC Sierra 1500 Pickup Truck Four-Wheel Drive Automatic](https://static.cargurus.com/images/forsale/2026/07/31/00/55/2021_gmc_sierra_1500-pic-4535919350000799801-1024x768.jpeg?io=true&width=640&height=480&fit=bounds&format=jpg&auto=webp)
2021 GMC Sierra 1500
AT4 Crew Cab 4WD
136,039 mi
Home delivery from Dallas, TX
Price includes $1,022 shipping
Good Deal
$31,016
- 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:
- Onyx Black
- Fuel type:
- Gasoline
- Interior color:
- Jet Black w/Kalahari Accents
- Transmission:
- Automatic
- Mileage:
- 124,109
- Stock #:
- 13722
- VIN:
- 1GTP9EEL3KZ151305
2019 GMC Sierra 1500
AT4 Crew Cab 4WD
124,109 mi
Home delivery from Everett, WA
Price includes $1,504 shipping
Good Deal
$31,050
- 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:
- Titanium Rush Metallic
- 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
Sponsored Listing
2024 GMC Sierra 1500
AT4 Crew Cab 4WD
31,690 mi
Highlands Ranch, CO
33 mi away
Fair Deal
$54,950
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 $26,896.00 to $85,452.65 with an average price of $33,402.56. 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
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 Boulder, CO?
The average GMC Sierra 1500 AT4 costs about $31,851.62. The average price has decreased by -1.5% since last year. The 315 for sale near Boulder, CO on CarGurus, range from $26,896 to $85,453 in price.
How many GMC Sierra 1500 AT4 vehicles in Boulder, CO have no reported accidents or damage?
288 out of 315 for sale near Boulder, 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 (or EV battery range).
What fuel types are available?
Diesel, Gasoline engines are available.
Relevant articles
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2027 GMC Sierra 1500 Pricing, Specs, and Release Date
GMC has redesigned the Sierra 1500 full-size pickup truck for 2027, with new styling, powertrains, and safety and convenience features.
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The Best Trucks Under $25,000 in 2026
New trucks cost more than ever, but the prices of used ones finally seem to be cooling. You still can't find the latest and fanciest full-sizes for budget prices, but fortunately, there are plenty of good trucks under $25,000 these days. Here, we've assembled a list of the best.
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