Display Gallery Page without Navigation Block

The primary content of the website is a gallery of images of cairns in different locations in the Mississippi River watershed.

Currently navigation is via a main menu on the left side of the page.  I am developing an interactive map to filter and otherwise zoom to a specific location.  Once the location is found, clicking on the location will display the image and text about that location in an overlay.

Both the menu navigation and the map navigation will be available for the user.

My question is in regards to displaying gallery content.  In the current implementation, the main menu is always displayed for each image in the gallery.  Since the map navigation displays the page in a popup overlay, I only want to display the image and the text, no main menu.  Note, these are not static html pages and ?format=main-content will not work.

Is there a way to pull just the image and text from a gallery item?

The first attachment is a display of the map zoomed in to a subset of locations.

The second attachment is the overlay displaying the image and text from that location.  My goal is to remove the menu from the overlay in the second attachment.

Thanks,

Michael