Adding the mapConfig section to the options for our app

options.js

var options = {
    menuItems: [
        { name: 'Current Fires', eventToRaise: 'View:CurrenFires' },
        { name: 'Historic Fires', eventToRaise: 'View:HistoricFires' },
        { name: 'Fire Danger Map', eventToRaise: 'View:FireDanger' }
    ],
    toolItems: [
        {name: 'Search', eventToRaise: 'View:Search', iconclass: 'entypo-search'},
        {name: 'Stats', eventToRaise: 'View:Stats', iconclass: 'entypo-chart-bar'},
        {name: 'Layer List', eventToRaise: 'View:LayerList', iconclass: 'entypo-map'},
    ],
    mapConfig :{
        initialExtent: { "xmin": -14106000, "ymin": 2834000, "xmax": -6896000, "ymax": 6385000, "spatialReference": { "wkid": 102100 } },
        basemaps: [
            {
                'name': 'National Geographic',
                'type': 'ArcGISTiledMapServiceLayer',
                'visible': true,
                'url': 'http://services.arcgisonline.com/ArcGIS/rest/services/NatGeo_World_Map/MapServer'
            },
            {
                'name': 'Topo Map',
                'type': 'ArcGISTiledMapServiceLayer',
                'visible': false,
                'url': 'http://server.arcgisonline.com/ArcGIS/rest/services/USA_Topo_Maps/MapServer'
            },
            {
                'name': 'Satellite Imagery',
                'type': 'ArcGISTiledMapServiceLayer',
                'visible': false,
                'url': 'http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer'
            },

        ],
        operationalLayers: [
            {
                name: 'Red Flag Warnings',
                url: 'http://svinetfc3.fs.fed.us/ArcGIS_NPSG/rest/services/NPSG/Fire_Watches_Warnings/MapServer',
                type: 'ArcGISDynamicMapServiceLayer',
                visibleLayers: [1],
                visible: true,
                opacity: 0.8
            },
            {
                name: 'Fire Perimeters',
                url: 'http://wildfire.cr.usgs.gov/ArcGIS/rest/services/geomac_dyn/MapServer',
                type: 'ArcGISFeatureServiceLayer',
                visibleLayers: [1],
                visible: true,
                opacity: 0.8
            }
        ] 
    }
  };