Mike Moran wants you to know sitemaps are not required for search engines to crawl your site. He explains that pages designed properly allow Google and friends to "happily" add your pages to their indexes. But what if the sitemap isn't built correctly?
Moran suggests checking Google's, Yahoo's and Microsoft's search engine to make sure your site's pages are indexed. If you have 60,000 pages, the best you can do is spot check with a method he provides. Rather than become fixated on sitemaps, keep testing to ensure your pages are being indexed.