If you check, you can probably find mysteries that cover about any theme you want. Here is one of my favorite mystery themes - National Parks.
My first introduction to a mystery in a National Park was by Nevada Barr. It was called Track of the Cat and it occurred in Texas - naturally!! There are plenty more Anna Pigeon (she is the sleuth) mysteries and they occur in places all over.
Another introduction to a mystery in a National Park was by Dana Stabenow. I was introduced to this series featuring Kate Shugak in a National Park in Alaska thru a Mystery Reading Discussion Group at Firewheel Mall Barnes and Noble.
Between these two authors there are a lot of books to read - see the lists below. But if you have others to suggest, please leave a comment.
Here is a list of the Anna Pigeon books -
1. Track of the Cat (1993) Guadalupe Mountains National Park in Texas
2. A Superior Death (1994) Isle Royale National Park in Lake Superior, Michigan
3. Ill Wind (1995) Mesa Verde National Park in Colorado
4. Firestorm (1996) Lassen Volcanic National Park
5. Endangered Species (1997) Cumberland Island National Seashore of the coast of Georgia
6. Blind Descent (1998) Carlsbad Caverns National Park in New Mexico
7. Liberty Falling (1999) Statue of Liberty and Ellis Island National Monuments in New York City.
8. Deep South (2000) Natchez Trace Parkway in Mississippi
9. Blood Lure (2001) Glacier/Waterton National Peace Park in Montana
10. Hunting Season (2002) Natchez Trace Parkway in Mississippi
11. Flashback (2003) Dry Tortugas National Park, a grouping of tiny islands seventy miles off Key West
12. High Country (2004) Yosemite National Park in California
13. Hard Truth (2005) Rocky Mountain's National Park, Colorado
14. Winter Study (2008) Isle Royale National Park in Lake Superior, Michigan
15. Borderline (2009) Big Bend National Park in Texas
16. Burn (August 2010) New Orleans, Louisiana
Here is the list of the Kate Shugak books -
1. A Cold Day for Murder (1992)
2. A Fatal Thaw (1992)
3. Dead in the Water (1993)
4. A Cold-blooded Business (1994)
5. Play With Fire (1995)
6. Blood Will Tell (1996)
7. Breakup (1997)
8. Killing Grounds (1998)
9. Hunter's Moon (1999)
10. Midnight Come Again (2000)
11. The Singing of the Dead (2001)
12. A Fine and Bitter Snow (2002)
13. A Grave Denied (2003)
14. A Taint in the Blood (2004)
15. A Deeper Sleep (2007)
16. Whisper to the Blood (February, 2009)
17. A Night Too Dark (scheduled for 2010)