Every reputable math journal that I'm aware of tries to give you the LaTeX information you need to submit a paper. So I did a quick search and found this page. In the section "Preparing a manuscript for submission" it says,"The CMS recommends LaTeX for manuscript preparation and has prepared a sample LaTeX file for author review which generates this PDF output. Please ensure your pages are numbered, beginning with 1. For further information about style, formats, the use of LaTeX and the production of PDF output, contact the CMS by e-mail at: firstname.lastname@example.org."
At the page I've linked to you'll find you can download a sample tex file and the PDF output it provides. The e-mail ought to get you the answers that you might still have after checking out the .tex file.