Routing issue

Hi. I tried to route something in Death Valley, and it looks like cycle.travel is refusing to route a particular road. I looked at the OSM data earlier, and it's not obvious to me what the issues is. Can you take a look, in case this is a bug in something? Route:

https://cycle.travel/map?from=Saline%20Valley%20Dunes&to=Death%20Valley%20Junction&fromLL=36.7652113,-117.8517469&toLL=36.3017289,-116.414066

There's a direct dirt road between the two points, but cycle.travel is refusing to go below the lower warm springs. Everything here is unpaved, but that includes the roads it didn't refuse to route.

Thanks!