Rocky Mountain Puzzle Quilt Block

From our Free Quilt Block Patterns Library

by Julie Baird

This post contains affiliate links for which I receive compensation.

The Rocky Mountain Puzzle quilt block won't be a puzzle for long.

Not after you learn the secret!

Solve the puzzle with quick pieced HST and a bit of partial seam piecing. That's all there is to it.

Time to cut up and sew!

General Instructions

These abbreviations are used on this page:

  • SA - seam allowance
  • RST - right sides together
  • HST - half square triangle
  • BAC - background fabric

SA are 1/4" and pressed towards the darker fabric unless noted otherwise.

Starch your quilt fabric before cutting if you like crisp fabric. Learn more about starching here.

Step 1: Cut patches for a Rocky Mountain Puzzle

Rocky Mountain Puzzle patchwork designRocky Mountain Puzzle

The Rocky Mountain Puzzle design needs three fabrics: a background a medium and a dark. 

For our sample block employs a medium fabric (purple) as the background. 

We chose contrasting fabrics to differentiate between the two medium fabrics—a tone-on-tone solid vs. a polka dot. That's help the piecing stand out. 

Generations Quilt Patterns logo

Cutting Chart for a
Rocky Mountain Puzzle Quilt Block

~Traditional Piecing ~

PatchFabricQtyFinished Block Size
8" 12" 16"
1** BAC 5 2⅞" x 2⅞" 3⅞" x 3⅞" 4⅞" x 4⅞"
2** Dark 5 2⅞" x 2⅞" 3⅞" x 3⅞" 4⅞" x 4⅞"
3 Light 3 2½" x 2½" 3½" x 3½" 4½" x 4½"
4 Med 3 1½" x 3½" 2" x 5" 2½" x 6½"
Unfinished Block Size 8½" 12½" 16½"
Grid Size 1" 1½" 2"
**I prefer to cut my patches extra large for HST, stitch, and then trim them to size. If you prefer to do the same, add a bit extra to the measurements for Patches #1 and #2 above.

There is a chart further down in these instructions where you need it for trimming them to size.

These are some of the supplies I use to prepare and cut my fabric.

Step 2: Assemble the units


Make 10


We use the Quick Pieced method for making our HSTs.

If you plan to make many blocks, you may want to use another HST method like 8-at-a-time or triangle paper.

Draw a diagonal line from corner to corner on the back of either all the #1 or #2 squares. Mark whichever one is easier to see the line on. For the sample block, it's easier to see the line on the purple #2 fabric.

Mark either the #1 or #2 HST squares

Now I stitched this sample with my Sunday Sew-In gals (there's nothing like a day filled with quilting, good company, laughter and never-ending lattes!).

As luck would have it, my quarter inch foot was back at home.

And my Quick Quarter ruler was keeping it company!

Now there's no way I'm going to consistently eyeball a decent 1/4" away from the marked lines on those five pairs. (It's just not in my nature!)

But there's always more than one way to get things done in quilting!

So I simply marked the sewing lines instead—a quarter inch away from that center diagonal of the block.

Very easy to stitch with an open toe applique foot.

Sewing on the line'Love an open toe applique foot for this kind of sewing.

Below you can see a stitched #1/#2 (upper left), cut in half (upper right) and the two resulting HSTs with SA pressed to the dark.

Sewing HST

Repeat the process for the remaining pairs of #1/#2 squares.

Now check the accuracy of your stitching using the chart below. Trim as needed.

HST Dimensions

Block Size
Trim HST to…
8" 2½"
12" 3½"
16" 4½"

How'd you do?

Because I prefer sewing with oversized patches, trimming is always a necessary step in my piecing.


With RST, stitch four pairs of HST together as shown below. Press the SA in the direction of the arrow.

Sew pairs of HST togetherMake 4

Set two pairs aside until Step 3.

With the remaining two pairs, add a #3 square to one side and another HST to the other as shown below.

After stitching the units together, press SAs in the direction of the arrows so that the seams in Step 3 will nest.

Sew top and bottom units into rowsMake 2


Make 1


To make the center we use the 'partial seams' or 'puzzle piecing' method where only part of the first seam is sewn.

Add the remaining three #4 patches as you normally would.

Then, and only then, stitch the second half of the first #4.

Arrange your patches.

Four #4 and one #3 patch

Stitch half of the first #4 to the center #3.  Start your sewing from the edge with the #3 and #4 patches aligned.

The pin (red arrow) shows where to stop stitching. I don't usually backstitch here since there's just a bit of stitching. Nothing to put any strain on the individual stitches. 

If you feel better taking a backstitch or two...go ahead.

Sew half the seam of the first #4

After sewing, you can see it's partially sewn. The arrow points to the end of the stitching line.

The first partial seam is done

This partial seam is pressed flat first to set the seam, then out towards the #4.

Add the next #4 to the side containing the #3 and #4 patches.

Below the third #4 is added. (The red arrow points to the first partial seam.)

Adding the third #4

Add the final #4.

All that's left is to finish the second half of the first seam. 

Finish the first partial seam

The pin to the right of my fingers shows where this final seam will end.

I do overlap my stitches here to secure the seam.

Finish sewing the first #4

One final pressing and the center of the Rocky Mountain Puzzle looks like this.

The completed center

Step 3: Assemble your Rocky Mountain Puzzle

Arrange the units into the  design shown below.

Arrange the patches into the Rocky Mountain Puzzle design

With RST, stitch the units in the center row together. SA are pressed toward the center.

With RST, sew the rows together. Use pins as needed. 

Check out 'Perfect Points for Impeccable Patchwork' for help with matching points.

Our Rocky Mountain Puzzle quilt block is complete.

Front of finished Rocky Mountain Puzzle quilt block

And from the back so you can see how the SA all fit together.

Back of finished Rocky Mountain Puzzle quilt block

Our Rocky Mountain Puzzle is a puzzle no more!

Link to Free Quilt Block Patterns Library

For even more blocks to make...

These are my go-to resources for quilt block ideas. 

Can you see the library sticker on the spine of Jinny Beyer's book? Yep. I check this copy out of our local library every few months for research.

Maggie Malone's 5500 Quilt Block Designs is my all-time favorite quilt block resource!

Can you tell?

It's in color.

It's got a ton of blocks.

What's not to love?

Next on my 'must-have' list is Barbara Brackman's Encyclopedia of Pieced Quilt Patterns.

Unlike the Maggie Malone book, the blocks in this volume are hand-drawn and in black and white—no color—personally, I prefer colored drawings to work with.

This book is no longer in print.

If you can come by a copy expect it to be wickedly expensive. Once in awhile you can find it here on

UPDATE: Electric Quilt, in cooperation with Barbara Brackman has announced they plan to republish the Encyclopedia sometime in 2020. 

However, all is not lost if you can't find a hard copy.

BlockBase is the computerized version of the Barbara Brackman's Encyclopedia of Pieced Quilt Patterns.

It contains designs for over 4300 blocks—pretty much every block published from the 1830's through the 1970's.

It can be used with Electric Quilt and is a Windows based program.

In fact, there are instructions included so that you can pull up the digital patterns within Electric Quilt (PC version for now) without having to open up BB program.

UPDATE: Electric Quilt has announced that they will be rereleasing the standalone BlockBase software for BOTH PC and MAC in 2020.

This is terrific news.

Finally there's The Quilter's Album of Patchwork Patterns by Jinny Beyer.

Lots of detail and in color, it is a beautiful volume. That said, I check it out of my local library on a regular basis instead of purchasing it—can you see the library sticker on it's spine. Yep, it's from the Plainfield Public Library.


Simply because I own the previous three references and find this the least user-friendly of the group.

And it does make a fabulous coffee table book!

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