My husband and I have had a rental property in WV for around 11 or 12 years. In Dec. 2019 we purchased another rental property in OH. Although the properties are in different states they are only about ten minutes from each other. We are a military family and have to travel about 7 hours away to check on/work on these properties. For most of the year we were only traveling to tend to the WV property but we made two trips where we worked on our WV property but also looked at the OH property to purchase and then closed on/did work on it the next trip. How would we break up the travel expenses for these two trips seeing as though we tend to both properties when we travel there?

I wouldn't overthink this. Just split the mileage in half between the two properties when you're looking at both. 

As you grow and get more complex, consider something that ties into your accounting software.  For my business, I have vehicles that aren't solely used for the business so we capture those miles in a program called trip log.  This program integrates with our quick books for that business.  There are many others out there to consider.  So he's right don't overthink it, try a few out to see what you like, make a decision and move forward.

@Natalie I utilize the app MileIQ to track mileage. You can go in and manually change a trip to business and it will count the mileage for you for the year!

@Natalie Lindsey

If those trips were only for the new property, maybe it would be worth it to split. Since every trip involved both properties, I would just attribute it to the old property. Yes, it's a minor shortcut and ignores the rules, but I would sign off on it.