How can I add reference lines at specific degrees/minutes/seconds?

[KaraG]

Hi everyone,

I need to add reference lines at specific latitudes, like the image here: <https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=113031&inline>

Here's what I've tried/found so far:

- I found ESRI's base layer lat/long grid, but the resolution is not fine enough (it only goes to 1 degree)
- I found another group of files hosted by USGS (I believe) that had the resolution I need, but not the extent (I need it to cover California but also into the Pacific Ocean)
- I saw something about a "Reference Latitude" tool, but I don't appear to have the proper license to use it
- Lastly, I saw references in a couple of semi-similar questions to the "Create Fishnet" tool, but I honestly can't figure out what parameters to use to get what I need -- if someone could break this down for me, I would so appreciate it. I'm using the California Teale Albers (meters) projection.

This seems like something that would be really simple, but I can't figure it out. Thanks for any ideas/help.

[curtvprice]

One more thing - as I mentioned up-thread, if straight lines in lat long become curved on your map, you may need to densify your lines (there's a tool for that, and you can also do this in the editor).  Though I think the project tool may do that for you (maybe not in ArcMap).

[DavidPike]

Ah OK.  Did you set the data frame spatial reference/coordinate system to WGS84 before running it?  It should pick that up as the coordinate system fo the defined xy origin and y coord.  If not, try defining the coordinate sytsem first as WGS84 (WKID 4326) with the Define Projection tool and then use the project tool to go from WGS84 to your Projected system.

But also, you should probably just weigh up the need for accuracy/precision with this against the viewing scale the map will be at i.e. what is the purpose of the map, and would any viewer be able to tell any noticeable difference if you just drew the lines on?

[KaraG]

Update -- I tried defining the projection as WGS 1984, bringing it into my working dataframe and projecting to CA Teale Albers, and the lines looked the same as the image I pasted above. I wish I knew what the issue was, but I have no idea. So I tried the second suggestion of creating an excel table with coordinates along the latitude lines I wanted. I displayed the points in WGS1984 and then used the Points to Line tool to create lines. I then brought that shapefile into my original dataframe and it lined up beautifully!

Thank you so much Curt and David for your help!