Hi Jim,
Here is the way to add mpk layer to the map, you just need to use ArcGISDynamicMapServiceLayer and the ServiceUri will be a LocalMapService.UrlMapService
LocalMapService localMapService = new LocalMapService("mpk file path");
await localMapService.StartAsync();
ArcGISDynamicMapServiceLayer arcGISDynamicMapServiceLayer = new ArcGISDynamicMapServiceLayer()
{
ID = "arcGISDynamicMapServiceLayer",
ServiceUri = localMapService.UrlMapService,
};
MyMapView.Map.Layers.Add(arcGISDynamicMapServiceLayer);
And there is a sample for that on GitHub. ArcGIS .NET Samples, in Desktop Samples > Layers > Dynamic Service Layer > ArcGIS Local Dynamic Service Layer Sample
Thanks,
Asser