This is probably a bit late for you Dan, but maybe it will be useful for others coming that way.
We came down from La Ceiba, turned right at Sava and turned onto a dirt road just before Olanchito, we had a road map of Honduras, The Treasure Map, as it is called! The dirt road was relatively good, got bad in a few places and when we got to the turn off for La Union the road was just a dirt base and it was raining so it got a bit slippery! We stayed a night at a very nice hotel in La Union, Hotel La Muralla, L250 with 2 double beds, private hot water bath and nice and clean with huge gates enclosing the hotel and parking! YOu can´t miss it, on the right on the main street, there are other cheaper places but we wanted to get out of the rain!
You have to go to the Cohdefor, to register to go to La Muralla national park, which is in the road parallel to the main road you come in -ask at the hotel. We were told that the visitor centre´s showers and toilets would be open but that the security guy wasn´t there and camping was free. So we went there and all was locked up and looking like it had been closed down for a while. We pitched out tent on the verandah and roughed it for a couple of nights. The taps weren´t working but we have a water filter pump and the stream was about a 10min walk on one of the paths. The walks are really nice, cloud forest, although pretty overgrown in parts, Geoff cleared the main 2 paths with his machete so if you go there anytime soon you should be sweet! Lots of birds! The road there was ok, a small river ford which was fine even at this time of year (rainy season).
La Union doesn´t see many tourists at all, so you see a real different part of life in Honduras. Very friendly tho.
There is a gas station in La Union and it looks pretty old but the gas we got was good!