rigsize

Forest River Sierra 3710HBFB mattress size

Years 2026Sold as SierraLength 42' 9"Sleeps 7
66 in 80 in
To scale. Dashed: a regular queen.
Main bed66 × 80 inOlympic queen

That's an Olympic queen, 6 in wider than a regular queen. RV mattress sellers stock it; a regular queen would leave 6 in of platform bare.

Forest River spec sheet, 2026.

Mattresses in 66 × 80 in

We may earn a commission when you buy through some of these links. It doesn't change which mattresses we list.

Great all around
RVMattress.com Signature Hybrid

RVMattress.comSignature Hybrid

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

Sleep Foundation: Best Mattress Overall Read review

$1,465Olympic Queen - 66x80 · list priceSee price
Best value
RVMattress.com CopperFlex Essential

RVMattress.comCopperFlex Essential

  • All-foam
  • 6 in thick
  • five comfort options
$799Olympic Queen - 66x80 · list priceSee price
Firm
RVMattress.com Plank Firm Luxe

RVMattress.comPlank Firm Luxe

  • Hybrid
  • 13 in thick
  • Firm / Extra Firm
$1,865Olympic Queen - 66x80 · list priceSee price
Cooling
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

$1,999Olympic Queen - 66x80 · list priceSee price
RV hybrid
RVMattress.com CopperFlex RV Hybrid

RVMattress.comCopperFlex RV Hybrid

  • Hybrid
  • 10 in thick
  • Medium-Firm
$799Olympic Queen - 66x80 · list priceSee price
Custom size
Mattress Insider Luxury Gel Memory Foam

Mattress InsiderLuxury Gel Memory Foam

  • Memory foam
  • 8 in thick
  • not stated
Made to 66 × 80 inGet a quote

The 3710HBFB floorplan

Forest River Sierra 3710HBFB floorplan, 2026

Forest River's 2026 3710HBFB floorplan.

Is this your 3710HBFB?

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

YearModelLengthSleeps
2026Sierra 3710HBFB42' 9"7

Other Sierra mattress sizes

3550BH3880BH3900HBLR3990FL4002FB4003MBAll Sierra floorplans

Sources

  1. Forest River (forestriverinc.com), archived copy: https://web.archive.org/web/20251104202042/https://forestriverinc.com/rvs/sierra-fifth-wheels/3710HBFB/12073
  2. Forest River (forestriverinc.com), archived copy: https://web.archive.org/web/20251104042207/https://forestriverinc.com/rvs/ImageHandler/296237/2026_Sierra-3710HBFB-2026%20copy.webp
  3. funtownrv.com: https://www.funtownrv.com/product/new-2026-forest-river-rv-sierra-3710hbfb-3454109-5

Questions

What size mattress is in the Forest River Sierra 3710HBFB?

The main bed is 66 × 80 in (Forest River spec sheet, 2026).