Import OSM Relation into Umap

Search in uMap is fairly basic, and will give only markers.

But you can import linear data in two ways :

1. Dynamically load data through overpass
2. Download your data otherwise, and import it once.

In your case, as the data should never change, I would go on solution 2, to reduce the load on the servers.

Here are the details :

1. Got to overpass-turbo, to build a query like this one
2. I put only the county you cited, but you can add as many as you want with more rel(#county_id); in the parenthesizes, they create a union.
3. Then click Run, to check that it's what you want.
4. Click Export, then download (GPX is a fairly standard format, others are possible).
5. In uMap, click on the up arrow, in the right menu (see this guide for details), choose your file, the same format as when downloading, a new layer...
6. And click import !
7. Then you can change the settings of the layer, one useful with this kind of data is in "Advanced properties", "simplify", it will make displaying at lower zoom faster.

Hope this helps, please ask if you need more assistance.

Regards.