In his poem "At Barstow," Charles Tomlinson directs the reader towards the reality of the decline after the rise and climax that everyone and everything experiences. The author is creative in using the small western town of Barstow (which could be any western town) as his setting. He also uses a once glorious movie figure to prove his point. The author is successful in illustrating the theme through the use of descriptions of Barstow and Roy Rogers which once had much glory, but now just goes even further into decline every day. His message hits the reader with very intense power through undertones that remind the reader that one day they too will decline.
After the first two lines, the reader already has a picture of a very small, lonely place that is 3000 miles west of nowhere called Barstow. Just when the reader is thinking that this town is very worthless, Tomlinson shows that although this town is a dump, it still serves a useful function, at least for truckers:
A faint flavour of Mexico in the tacos
tasting of gasoline. Trucks refueled
before taking off through space.

Barstow has become a place where truckers stop over to refuel and to grab a bite to eat before going back on to the lonely road. That lonely road is a very empty void, with people and stops far and few between, just as space is a large void with great distances between planets and other stellar objects. It is also safe for the reader to assume that the food isn't of the best quality or that the eating conditions aren't the cleanest. The food most likely doesn't really taste like gasoline, but there may be a strong stench of it in the air. Since most of our taste is based on smell, the reader would be safe to assume that there is a strong smell of gasoline in the air. This may also be the author's way of illustrating further the smallness of this place, indicating that the eating establishments are relatively close to the gas station.
Barstow comes across as a collection of very dismal homes where people that would always talk of plans to leave as soon as they can would live. The author also smothers his description of Barstow as a place where an unnamed someone is separating themselves from nothing:
…someone lived
in the houses with their houseyards wired
like tiny Belsens.

Just from his description of each of this town, it seems that even death is too exciting for them, although he refers to the yards as tiny Belsens. (Belsen was a tiny Nazi concentration camp in WWII) The author seems to be indicating that the people of Barstow are prisoners of their own hands and although they can leave at any time, they don't.
The poet then proceeds into further details of the ominous atmosphere using another murky image. He mentions The Gotterdammerung, (Twilight of the Gods) which is an opera. In the opera, the god's world is destroyed:
…The Gotterdammerung
would be like this. No funeral pyres, no choires
of lost trombones.

The author seems to be comparing Barstow to this world that is in the midst of destruction. An un-named power is destroying Barstow just as the god's destroyed their world in The Gotterdammerung. However an ironic point is that when the world came to an end in the opera, it was a grand and tragic end. Barstow is just silently falling into decline. Tomlinson then shows that this place did have a silent fall, that wouldn't have been noticed unless someone was watching:
…An untergang
without a clang, without
a glimmer of gone glory
however dimmed…

These lines imply that Barstow had met it's decline without much fanfare, without much recognition, and without much notice.
The town does have some life left in it, but not much. The poet describes a hotel where a famous icon had once stayed:
…At the motel desk
was a photograph of Roy Rogers
signed. It was here
he made a stay…

Again using irony in his writing, the author talks about how Roy Rogers didn't leave like he would have been expected to and what his stay was like at this motel in this small town:
…He did not
ride away on Trigger
through the high night, the tilted
Pleiades overhead, the polestar low…