2020 GMC Sierra prices in Montana
The median pre-owned asking price for a 2020 GMC Sierra in Montana is $35,924 based on 34 active listings.
As of August 14, 2026, the median asking price for a used 2020 GMC Sierra in Montana is $35,924, based on 34 active dealer listings tracked by VinAssessment.
◷ Updated August 14, 2026 ▤ 34 active dealer listings, refreshed daily ⛭ Generation: 2019–2021 Methodology →
Typical: $31,031–$43,896 — the middle half of 34 asking prices
Why the wide range? Price depends mostly on configuration and mileage — see below. This spread covers the middle 96% of asking prices: we exclude the cheapest and priciest 2% (payment-priced ads, typos, salvage) so outliers don't distort it.
What moves the price on a 2020 GMC Sierra
The $31,031–$43,896 typical range isn't randomness — two factors explain most of it:
Asking prices run about $48,990 under 15K miles and fall to $30,974 over 105K miles — roughly $1,700 for every 10,000 miles.
The SLE typically asks $28,980, while the Denali asks $42,989 — same year, same market.
Find your mileage and trim in the configurator below.
Configure the exact car
Modelled from 946 real asking prices, adjusted for mileage and location. Not a formal appraisal.
What would a 2020 GMC Sierra cost per month?
Estimate the monthly payment on a $42,989 vehicle. Move the numbers to match your own loan.
Estimate only. Excludes tax, title, registration and dealer fees, and assumes a fixed-rate loan with equal monthly payments. Your actual rate depends on your credit and lender.
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2020 GMC Sierra: a fair price for your mileage
A 2020 GMC Sierra sheds roughly $1,700 for every 10,000 miles. Find your mileage below.
Fair price by mileage and trim
| Mileage | All listings | Denali | SLT | AT4 | Elevation | SLE |
|---|---|---|---|---|---|---|
| Under 15K miles | $48,990 | $54,394 | $40,197 | $44,445 | — | — |
| 15K–30K miles | $45,194 | $61,065 | $44,320 | $46,386 | $38,573 | — |
| 30K–45K miles | $44,293 | $56,980 | $39,910 | $44,494 | $37,224 | $33,500 |
| 45K–60K miles | $40,348 | $45,988 | $39,010 | $42,202 | $34,607 | $33,900 |
| 60K–75K miles | $38,548 | $41,600 | $36,634 | $39,797 | $32,990 | $33,648 |
| 75K–90K miles | $36,451 | $40,544 | $34,790 | $37,997 | $31,880 | $30,766 |
| 90K–105K miles | $34,044 | $39,991 | $33,277 | $35,749 | $29,995 | $27,900 |
| Over 105K miles | $30,974 | $40,000 | $29,887 | $32,600 | $26,297 | $23,995 |
Medians of live asking prices per band and version; “—” means fewer than 3 matching listings. National data.
Fair price by mileage — all versions combined
| Mileage ⓘ | Based on ⓘ | Fair price ⓘ | Typical range ⓘ |
|---|---|---|---|
| Under 15K miles | 23 listings | $48,990 | $39K–$57K |
| 15K–30K miles | 48 listings | $45,194 | $42K–$59K |
| 30K–45K miles | 137 listings | $44,293 | $39K–$57K |
| 45K–60K miles | 287 listings | $40,348 | $37K–$48K |
| 60K–75K miles | 480 listings | $38,548 | $35K–$42K |
| 75K–90K miles | 553 listings | $36,451 | $33K–$40K |
| 90K–105K miles | 524 listings | $34,044 | $31K–$37K |
| Over 105K miles | 1,008 listings | $30,974 | $27K–$36K |
Same trim and condition assumed — mileage is the biggest lever after configuration. National data; Montana prices track it closely.
2020 GMC Sierra: price by trim
| Trim | Based on ⓘ | Median price ⓘ | Typical range ⓘ | Where it sits ⓘ |
|---|---|---|---|---|
| Denali | 946 listings | $42,989 | $37K–$53K | |
| SLT | 813 listings | $33,980 | $30K–$37K | |
| AT4 | 620 listings | $37,180 | $33K–$41K | |
| Elevation | 353 listings | $30,300 | $27K–$33K | |
| SLE | 197 listings | $28,980 | $25K–$34K |
National data; Montana prices track it closely.
Price history
Median asking price by month — national · shaded band is the typical range (25th–75th percentile)
The median listing price for a 2020 GMC Sierra is $35,989 (August 2026) — up 2.9% from $34,990 in April 2026.
Monthly price table
| Month | Median price | Typical range | Vehicles listed |
|---|---|---|---|
| August 2026 | $35,989 | $30K–$42K | 385 |
| July 2026 | $35,989 | $30K–$43K | 597 |
| June 2026 | $36,234 | $30K–$43K | 338 |
| May 2026 | $36,244 | $30K–$43K | 74 |
| April 2026 | $34,990 | $30K–$43K | 91 |
2020 GMC Sierra inventory across the U.S.
Keep exploring Sierra prices
2020 GMC Sierra · $35,924 typical · 34 listingsOther GMC Sierra years
Live 2020 GMC Sierra listings, priced by VIN
Every VIN links to a full market report: decode, active listings and the local price band. Shop 2019–2021 GMC Sierra listings on VehiSales →.
More 2020 GMC prices
Own a 2020 GMC Sierra? See what it's worth →
Frequently asked questions
Why do 2020 GMC Sierra prices range from $23,290 to $54,902 in Montana?
The spread comes down to configuration and mileage: higher-mileage, base-configuration examples sit near the low end, while low-mileage and premium configurations reach the top. Half of all listings fall between $31,031 and $43,896 — see the mileage and trim breakdowns above for where a specific vehicle lands.
How much should mileage change the price of a 2020 GMC Sierra?
Expect roughly $1,700 less for every 10,000 miles on the odometer. A 60K-mile example should cost about $5,100 less than a 30K-mile one of the same trim — check the fair-price-by-mileage table above for your band.
Do GMC Sierra prices in Montana differ from the rest of the country?
Yes. The average in Montana is $37,908, which is $567 above the national average of $37,341. Local supply, demand and transport costs all play a part.
How many 2020 GMC Sierra are for sale in Montana right now?
34 in total, nearly all pre-owned. Counts refresh daily from live dealer inventory.
How we calculate these prices
We track 34 active listings for this vehicle across dealer sites nationwide, updated every day. Average and median are computed from real asking prices on live listings. We exclude the top and bottom 2% of prices to remove data errors, salvage titles, and monthly-payment figures posted as if they were sale prices. Prices reflect dealer asking prices — not final sale prices — and exclude taxes, fees, and incentives. Trim and mileage move the price more than any other factor; see the breakdowns above.
Want the original factory equipment and MSRP behind a specific car? See the factory window sticker for this Sierra →
Shopping for this car?
Check individual VINs before you buy — decode the exact trim and mileage, see every active listing, and how each price compares to the local market.