So, a little digging around turned up this from the Mohican Hills Citizen Winter 2007 issue:
Phillips property fenced As you drive or walk up MacArthur Boulevard, you may have noticed a long, rather prominent new fence along a stretch of seemingly empty property adjoining the road—across from Glen Echo Park. What, if anything, does the new fence suggest? Well, first of all, if you look up the hill, you might glimpse an old stone house, now vacant. House and land are owned by Leland Phillips. He has assured the Tulip Hill Citizens Association (you can check their web site, www.thca.net ) that the fence was built to keep out trespassers who have vandalized the property (even used the house as a paintball target!). The Association has no reason to believe he plans to develop the property. (By the way, in our April 2003 Mohican Hills Citizen, p.8, we said that many folks mistake this house, known as the "Stonehaven House," for a Baltzley brothers "castle." But it was built much later, in 1937, than the "castles." Its builders and first occupants were Llewellyn and Carolyn Edwards.)
The Maryland Historic Society has a lot of interesting background on the house and the original owners at this link:
https://mht.maryland.gov/secure/medusa/PDF/Montgomery/M;%2035-44.pdf