"at its close" is correct and commonly used in written English.
It is typically used to refer to the end or conclusion of something. Example: The conference was a great success, with insightful discussions and productive meetings. However, at its close, it was clear that there were still some unresolved issues that needed to be addressed.
Born in 1819, he lived on until 1877, and his work thus spanned the gap between the formalized style that prevailed at the beginning of the century and the wholly new techniques that were developed at its close; it would be hard indeed to think of a painter of his general period who had a more powerful influence on the generation of the Impressionists.
A royal commission, though it does not have prosecutor powers, or the ability to compel people overseas to give evidence, can refer matters it believes warrants it to police, and at its close provides a comprehensive list of recommendations to governments and institutions to ensure errors of the past are prevented from happening again.
In deference to this impossible task, she dates almost everything -- either incorporating the composition date in the poem's title or appending it as an italicized note at its close.
McCreesh, meanwhile, was alive to the score's every emotional shift, from the grand ceremonials with which it opens to the shattering grief at its close.
Overall, Punching In is an interesting social study, but it seems to lack conclusive answers at its close; does the author learn what he set out to discover?
Frankel tells who had the most in-depth training, who offered the best incentives (the Starbucks 20-hours-equals-insurance gimmick is real) and whose employees were the most willing to "drink the corporate Kool-Aid". Overall, Punching In is an interesting social study, but it seems to lack conclusive answers at its close; does the author learn what he set out to discover?
At its close the ILF was spending some £250m on about 17,000 people.
Its slowly shifting sound clusters fracture into bewildering dissolution at its close.
Yet that was a story with something substantial at its close.
At its close, the second season finally solved the mystery of the first.
The shout from the arena of "remember Tibet" at its close was nothing if not timely.
