rigsize

Keystone Alpine 3100RE mattress size

Years 2026–2027Sold as AlpineLength 34 ft 11 inSleeps 4
70 in 80 in
To scale. Dashed: a regular queen.
Main bed70 × 80 inRV king

That's an RV king, 6 in narrower than a regular king (76 × 80 in). A regular king won't fit, so get an RV king in exactly 70 × 80 in.

About the RV king size →

Dealer report, 2027. A reported size, not a guarantee: measure your platform first.

Mattresses in 70 × 80 in

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Top pick
RVMattress.com Signature Hybrid

RVMattress.comSignature Hybrid

  • Hybrid
  • 13.25 in thick
  • Soft / Medium / Firm

Sleep Foundation: Best Mattress Overall Read review

$1,865RV King - 70x80 · list priceSee price
Best value
RVMattress.com CopperFlex Essential

RVMattress.comCopperFlex Essential

  • All-foam
  • 6 in thick
  • five comfort options
$799RV King - 70x80 · list priceSee price
Reviewers' favorite
RVMattress.com Aurora Luxe Cooling

RVMattress.comAurora Luxe Cooling

  • Hybrid
  • 13.25 in thick
  • Soft / Medium / Firm

Sleep Foundation: Best Mattress for Temperature Regulation Read review

$2,465RV King - 70x80 · list priceSee price
Best hybrid
RVMattress.com CopperFlex RV Hybrid

RVMattress.comCopperFlex RV Hybrid

  • Hybrid
  • 10 in thick
  • Medium-Firm
$1,065RV King - 70x80 · list priceSee price
Best all-foam
RVMattress.com Plank Firm

RVMattress.comPlank Firm

  • All-foam
  • 10 in thick
  • Firm / Extra Firm

Mattress Clarity: Best RV Mattress for Heavy People Read review

$1,532RV King - 70x80 · list priceSee price
Custom size
Mattress Insider Park Meadow Encased Coil II

Mattress InsiderPark Meadow Encased Coil II

  • Hybrid
  • 8 in thick
  • cushion-firm

Sleep Foundation: Best Mattress for Pressure Relief Read review

Made to 70 × 80 inGet a quote
Bedroom in a Alpine

The Alpine bedroom. Measure the platform, not the old mattress, before you buy.

The 3100RE floorplan

Keystone Alpine 3100RE floorplan, 2027

Keystone's 2027 3100RE floorplan.

Is this your 3100RE?

Check the year and length against your RV before you order.

YearModelLengthSleeps
2026Alpine 3100RE34 ft 11 in4
2027Alpine 3100RE34 ft 11 in4

Other Alpine mattress sizes

Sources

  1. Keystone (keystonerv.com): https://www.keystonerv.com/product/alpine/luxury-fifth-wheels/floorplans/3100RE

Questions

What size mattress is in the Keystone Alpine 3100RE?

The main bed is 70 × 80 in (Dealer report, 2027).