How about a framed display of arrowheads he has found with a map showing where he found each one? You could also consider getting him a book on arrowhead identification or a kit for cleaning and preserving the arrowheads. Another idea could be a trip to an arrowhead hunting destination that he has always wanted to visit.
Or you can get him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.