There might still be an operating wigwag signal at Devils Lake State Park. When I was last there about a decade ago it was still there and operational (and for revenue service no less!)

Otherwise the IRM has a really good collection of railroad signals. Many are actually in use on the mainline (so crews have to be familiar with even the biblically accurate railway signals along with all sorts of fun obscure variations. And if I remember correctly as you first enter and cross the streetcar loop and the steam shop/long barn sidings (long enough to store the entire Zephyr trainset on one track, as well as where quite a few cosmetically restored locomotives are stored including multiple articulated locomotives and a DDA40X) there's a wig wag protecting the crossing