If you look at their site they sell "standard lengths 3'-6'". A lumber yard will order it for you and the lengths should be random 6' to 20' in length. Personally I would order it locally from the lumberyard.

I agree with millworkman, and I'd also see if local salvage yards have any flooring to pick through.

Just a strange idea: when in heck did 3'6" become 'standard' length for flooring? I'd expect it from the plasticky laminates and such, but not for real wood flooring!

I found a bunch on Craigslist, but only because I was persistent and waited. Otherwise I'd also recommend going with the local lumberyard.

If your doug fir is like mine, the new stuff will match quite nicely, with the sole caveat that it's most likely all clear vertical grain and won't have any knots or other irregularities like the original stuff.

The mean pcs in lengths from 3' to 6'.

Thank you for the responses! Something I read made me worry about using new wood from a lumber yard instead of finding old salvage wood. They said that newer wood had too much moisture and would cause a bunch of shifting of the floorboards when it got hot or cold. Should I worry about that?

Also, the lumber yard asked if I want v groove or buttline. What are the differences between those?

Thanks again!

"Something I read made me worry about using new wood from a lumber yard instead of finding old salvage wood. They said that newer wood had too much moisture and would cause a bunch of shifting of the floorboards when it got hot or cold."
Order kiln dried wood, or let the wood sit in the house a few weeks to equilibrate. Even ancient wood will expand and contract a bit as humidity changes.

V-Groove or Buttline? Clarify with the lumber yard, but around here, that's the shape of the place the boards join. V-groove has a beveled edge on each board, so you see a v-shaped groove between boards. Buttline has squared edges so the boards meet (butt together) with no space or groove.

TIP: check the new flooring against the old before you start. If the tongues match, but the new stuff is too high, get a plane and plane the TOP of the board to match the heights. It makes sanding easier.

You definitely want butt joints -- v-groove means they have little bevels between the boards, which is a modern look that won't match (unless your original floors have grooves between the boards?).

Here's an image of Southern Yellow Pine with the V-groove; you can see how it's beveled on the top edge, which is what you DON'T want:

(from a current eBay auction)

You want regular tongue and groove with butt joints, no V-groove: