One hundred years ago in 1910 American elms shaded American streets. Since then, most of us have grown immune to the handwringing over the great American elm die-off, which does represent a plant pathological tragedy that's left our urban landscapes impoverished of elms and of their grace and vase-shaped amenities – and of the elm's unusual capacity among trees to tolerate domestication. The American elm's story is an old one, and it warrants grief.

The outline of our loss of the elms and how it happened is easily recited. In 1928 a shipment of elm timber from the Netherlands to Ohio brought a fungal pathogen with it. The fungus (Ophiostoma ulmi, formerly known as Ceratocystis ulmi) colonizes the vascular tissue of American elm (Ulmus americana), as well as other elm species. The fungus disrupts the flow of water and nutrients within infected trees, and the limbs of affected trees wilt and die. Dead branches in an elm canopy are known as "flagging." The disease is known as Dutch elm disease (DED). It spread rapidly from Ohio to all of the states east of the Mississippi River and even to the western states, reaching Colorado and Fort Collins in the early 1970s.

Bark beetle vectors made the spread of DED possible. When bark beetles (Hylurgopinus rufipes and Scolytus multistriatus, both scolytid beetles) feed on diseased elms, they acquire propagules of the fungus, which they carry to healthy trees, where the fungus takes off anew. The consequence of all this is that DED killed off the most loved tree in the American urban landscape.

What shocked me when I first came to Colorado is seeing remnant plantings of American elm growing all over the historic parts of Fort Collins. There's nothing like it in the country anywhere east of here. Drive over to the Avery House, for example, and you'll see elms growing on the grounds – as you'll also see on the grounds of the nearby courthouse and St. Joseph Catholic Church. Go up to City Park and over to Grandview Cemetery; there are elms. Double-back across town to Library Park and the old Fort Collins High School; you'll see elms. You might start to ask yourself, 'Where aren't there elms growing in Fort Collins?' The Old Town business district is one place without elms. Another is anywhere south of Prospect Road. But also, rows of elms don't line College and Mountain Avenues, like they must have done at one time in the city's past (which is not to suggest that there aren't magnificent – and some not so magnificent – individual elm trees to be seen along College and Mountain Avenues, only that the sight of an elm-lined avenue in Fort Collins has been lost to DED).

Actually, I learned from the Fort Collins assistant city forester that the city never followed a grand design of lining city streets with elms. What seems to have happened is a Fort Collins bank in the 1910s distributed elm seedlings to its customers, who naturally planted them out.

Then in the 1970s and 80s, Fort Collins lost upwards of a couple thousand elms to DED. The rate of loss has slowed in recent years, to less than ten trees per year (and the fascinating reason for that reduction in the incidence of DED may relate to a shift in the predominant bark beetle species feeding on the elms... but that's another story). Still, the most spectacular planting of elms in Fort Collins – one that was planted by design and which remains free of DED – is located around the Oval at Colorado State University (CSU).

The CSU Oval is the central feature of the oldest part of campus. It includes an allée, which was planted to American elm in 1880, only ten years after the college's founding. The drive around the Oval was laid out in 1909, and the elms on the perimeter were planted in 1922, which coincided with an important period of campus construction.

I spoke with CSU's landscape architect about the elms and how they're managed to maintain tree health. It turns out – as you'd probably expect – CSU follows an integrated program. An arborist came this spring and pruned out any limbs showing squirrel damage or representing a hazard. Applications of insecticide periodically reduce the numbers of the European elm scale (Gossyparia spuria). These applications seem particularly effective in maintaining tree health, the CSU landscape architect said. In addition to pruning and managing scale, the landscape architect said they watched for soil compaction. It's one reason – in deference to the elms – that the Taste of Fort Collins was moved away from the Oval... But Barack Obama's rally in October 2008 was not. If it's any consolation to the elms, my daughter – who was there – remembers Obama remarked on the attractiveness of the Oval and the elms. 

One evening last week after dinner, my daughter and I went over to the Oval to admire the elms. We ended up walking around the perimeter and counting the number of trees. On the perimeter we counted 48 trees. Down the central allée, we counted 31 trees, which brought our total to 79 trees. That number differs from the 65 trees that CSU reports as being on the Oval, but our count included 12 replants. CSU's landscape architect told me they replanted removed tree with the DED-resistant Valley Forge cultivar of American elm or with a similar American elm cultivar (rather than with a resistant Asian elm cultivar).

You owe it to yourself to go visit the Oval. Look at the elms, and admire their remnant example of what American cities and towns used to look like. Since CSU isn't in session right now, the parking is easy, especially in the evening and on weekends.

Your wanting to admire the elms is a good impulse, but it's not obvious – to most of us – how to go about doing it. Here are some suggestions:

•Stretch out on the grass in the middle of the day and take a nap.

•Take your significant-other across the street to Las Salsitas Mexican Grill (1010 South College Avenue). Get an authentic Mexican take-out lunch, and enjoy it together on the Oval.

•Photograph the elms in the most interesting way you can. Or, take any snapshot of the elms, to remind yourself later that the elms are still there.

•Walk around the perimeter of the Oval and down the allée. Note the spaces where the elms have died and have not been replaced. Consider counting the elms and spaces.

•Find the replanted trees. Ask yourself how they'll look, when they mature and all the elms on the Oval are different ages.

•Take your mobile device to the Oval. Sit on the grass, and find the Cans Around the Oval webpage. Read about the history and significance of this program, which collects food for the Larimer County Food Bank. It's an amazing story, which the elms have borne witness to.

•Go online. Find historic photographs of the elms. Print off the photos on the worst printer available to you, even if that only means printing-off the photos on a printer that's low on ink. Bring your grubby printouts with you to the Oval, and see if the images do – or don't – still capture a representation of what the elms look like in real life. (This will be more fun than it sounds; I promise.)

•After experiencing the elms in some way – and before you leave the Oval – reflect on how your perception of the elms has changed (or not) from what it was when you first stopped to admire them.

Having said all that, for God's sake don't hug the elms. People will think you're weird if you do, as they should. The elms are only trees.

And in the spirit of recognizing that an elm is only a tree, which DED has yet to kill, you might feel you don't need to visit the Oval to appreciate the amenities of a well shaded lawn. Many people would agree with you. Still, if you live in Old Town, go outside and see if you have an elm on your property. To do that, you'll need to consult an internet page somewhere, and confirm your identification. Share what you find with your spouse and kids.