Not can it be done, it looks beautiful. My DH did this - not only a DIY job, he had never worked with concrete before so it was all a "maybe this will work, let's try it" project! He says he set the outside stones carefully level (you will need to buy or borrow a 6' level, for something like this) on a packed sand foundation. Wet the sand; the slower concrete dries the stronger it is. He filled in the center with some rip-rap (we had some broken up concrete from past jobs), then poured over that, the usual quick-set concrete dry mix bought from HDepot, wet it down, and leveled it. Then let it dry for about a week, misting it down gently every day. Then he set the second course, filled in the center with concrete mix only, did the whole level/daily wetting. We live on a hill with slippery clay soil and a lot of continual settlement, and the stairs have been rock-solid perfect since 2003. HTH!

Mosaic came to mind first...of course!ahhaha Mosaic is the answer!!! But....... I did a bunch in those 1/2 marbles this fall for my mailbox,and just warn you.........I almost ended up in the hospital! they are sooooo slick. They will need to be replaced this spring. They look so great....but are are on their way out. I mosaic real close and tight, so my grout lines are not wide enough for traction..so with glass and tiles.. give yourself more grout space for stepping stones! Hazie

I was able to do something in my zone that may not work in zone 6 or for a long path, but I'll share it. I have a fairly short (15 ft?) sloped path to the back gate to our deck. I had a similar dilemma. On our property there happened to be some large fieldstone, and I found a number of rocks that were largish and irregular but flattish on one side--but a key thing is the flattish side was a little irregular, not slick and the rocks were thick enough to be partially buried. I dug out a hole for each rock so that it was actually set in the angle of the slope but with the downside slightly up, or the irregularity angled up or level, if you can picture that. I had to set each one fairly carefully, fill in with soil underneath, orient its "irregularities" to the best advantage of how I would place my feet going up and down. Most were only about a foot square or less but a few much larger are the first stones as you step down from the decking steps so you don't have to hunt for footing. Since this would have been a pretty narrow path, a few more are set alongside, but off centered, not exactly aligned. Planted dwarf mondo grass around the edges. This path has worked great for 4 yrs for foot traffic going up and down and while I tend to step on individual rocks, the path as a whole unit is stablized by the slightly angled, rough rock surface so you can step anywhere or roll a wheelbarrow on it. I have another area in which I may do a similar thing, will have to buy rock but now know which ones to hand-pick for the same result. Now, this worked for me because the slope itself took care of the drainage issue, I apparently do not have significant frost heave, and I could manage the installation and was willing to re-set an occasional stone (have not had to yet) , but it would seem less do-able for your many linear feet of path, you may need much more frost-heave protection. So you may need to look into doing the series of short terraced sections using rock or short lengths of timbers for cross pieces, and mulch or rock for the level areas. I've mentioned before on another thread, that you can find lots of photos by Google or in some books on "Paths" and sometimes under "Front Yard" design ideas. Also, look at your yard layout and see if you can determine the highest-priority "main path" on which to focus your efforts. It may be impractical (read:expensive; I have no doubt it can be done) to install paths on the bee-line approach to each of several areas; perhaps there will be one main, highly stable downhill path and some lesser paths.

oh - and sedums - not really happy about foot traffic. they are pretty watery inside, similar to ice plant (hell, ice plant may even be related to sedums, i dunno). every little piece of sedum that breaks off will grow if given the opportunity. i wouldn't necessarily say it is "invasive" per se, but i planted five small pint pots of "jenny's stonecrop" (aka "crooked yellow sedum") in my part-shade beds and i literally have enough of it now that i could fill six 12" pizza pans with it. everywhere a piece has broken off and rolled across, it has rooted and i'm starting to see little bundles root down here and there. another "bad" part about sedum is maintenance. it will NOT grow thick enough to prevent weeds from growing up through it. want to talk about fun? try spending half an hour ever week fishing all of the chickweed out of your sedum. moroever, try having your neighbor sign up for TruGreen's aeration & overseed service...and have them spread fescue seeds all over your bed in the process...now i'm picking out both chickweed and fescue sprouts. sheesh! i'm not sure of any groundcover that will lay flat and accomplish what you want, but i'm pretty sure spikemoss is what Urban Gardener had at their old location (on Boulevard, next to I-20), it was planted all over the south side of their property, it laid pretty flat (1-2" tall), may not have been spikemoss, but spikemoss surely looks like what it was. it was in a foot traffic area, so i guess it would hold up. i assume people would be using the stepping stones for the most part.