Oars are amazing instruments, but making them to become these wonders of balance, beauty and utility is tricky.
This little article is not describing the long road to producing the perfect oar, but rather the wood species that have worked for us. Anyway, before leaving the subject of oar making, let us say that a certain Pete Culler and his books have had a profound influence on us. Read them.

We have used 5 different woods for oars over time. Here's what we've learned.

The short hand story:

Go ash if you want to go 'green', and have oars that will last practically a lifetime of hard use.

Pick Alaskan Yellow Cedar for esthetics, ease of carving, rot resistance and light weight.

Forget about the rest.

First, all these, except ash, carries enormous environmental consequences. The lumber required for a projects like oars and spars needs to be clear and tight grained. Such quality only comes from old growth, virgin stands of conifers. There are preciously few of these left, so do we want to contribute to the demise of such an incredible ecosystem? Damn, it is hard to live in this world...

ASH
The only hardwood on the list, and by far the densest, hardest choice. Also the heaviest. Ash oars are strong and utilitarian, but needs to be well cared for to prevent decay from fungi.
The wood works nicely with sharp tools, and will carry a carved ridge crisply.
The finished oar have considerable heft to it, even with reduced scantlings, so pay extra attention to balance.
A good choice for oars that will see constant, heavy use, such as guided drift boats or small craft liveries.

ALASKAN YELLOW CEDAR
An overlooked choice for oars, AYC is creamy and smooth. Relatively soft, but extremely resistant to rot and decay. Strong for its weight, and with reasonable care, an excellent oar material.
One of the absolutely finest boat woods to work with hand tools. It is not uncommon to carve a pair of oars without ANY tearout or splintering, even accidentally working against the grain. And the scent is divine.
With prices on Doug Fir and Sitka Spruce going through the roof, AYC is even more attractive, and we find new places to use it every day.

WESTERN RED CEDAR
Soft, brittle and relatively weak, WRC is an outsider on this list. In fact, it wouldn't have made it at all if it wasn't for a pair of long oars we made years ago for personal use. Having pulled a 22' Umiak hundreds of miles these trusty oars are still the choice for a long passage. Go figure!
If it wasn't for this testimony, we would probably choose any of the other woods on this page before WRC, especially with the current prizes.

SITKA SPRUCE
Classic choice for light, strong and beautiful oars. Availability of clear, top notch material is becoming scarce, and the few suppliers out there are very expensive.
But if you have that special project, say a pair of wonderfully balanced spoon blade oars, you could justify the prize and karmic baggage associated with this dwindling conifer.
It works well with sharp tools, but spruce will tell you right away if you have opposing grain.

COASTAL DOUGLAS FIR
The standard for the working fisherman, up here in the Pacific Northwest. Or used to be, before the forests got butchered, and the ubiquitous outboard took over. The few remaining stands of quality lumber are highly coveted, hiking prizes up and up.
A difficult species to work with, even when the edge tools are keen and sharp. Splintering and tearouts are the name of the game, and extreme difference in density between early and late grain makes finishing of flat surfaces troublesome.
The one advantage of Douglas Fir is the probability of finding the occasional oar grade material in the teetering stacks of crappy framing lumber at the local yard, and thereby saving lots of money