Unless you select a waypoint the gps will default to the nearest one. The following may not be needed.
I would have approached it a little different and created a TRACK and saved it for the trapline. Mainly because I use Tracks all the time. Currently I only have one ROUTE on my gps. I created the Route on my computer using Map Source US Topo and the Routing Tool in the tool bar. The Route goes into the backcountry from a state highway on to logging roads. To fit my navigational needs I created the first waypoint at the location I would leave the state highway and start my journey into the backcountry. If I planned on intersecting the Route off a different road system I would do the following.
Because I do not have a local Route I cannot give you a fix answer based on experience, but I will give you a couple of options.
If I planned on intersecting the Route off a different road system I would do the following.
Option 1 is to select the waypoint that you want to start at using your waypoint option. Select the waypoint>Enter>GoTo>and follow the Bearing Pointer (Compass to that waypoint) select OFF ROAD and the pointer will take you to the waypoint.
Option 2:Select the Waypoint Icon>Enter>Menu>Find Nearest>you will be given a selection of Waypoints nearest your current location. You can scroll down until you find the Waypoint you want to start at, select Enter>GoTo>Off Road>COMPASS PAGE and the Bearing Pointer will point the direction you need to travel and give you the distance. Once at your selected waypoint you can easily use the map screen and the arrow pointer to locate the next waypoint or enter it use the Find waypoint and navigate to the next location.
MY PREFERRED METHOD IS TO CREATE A TRACK WITH Trap Waypoints along the Track. You have already created your waypoints and you will not have to recreate them. The goal is to create a clean Track identifying your trapline. Before leaving home select the Main Menu Page>TRACKS ICON>ENTER>if OFF is not selected use the rocker to select OFF. If there is a current Track on your unit you want to save this is the time to do it. Use the rocker and select save and Enter and select Yes or No to the question.
I am starting you out with a clean track so that you can clearly identify this trapline. Once you get out to your parking area, go to the Main Menu Page>Tracks icon>Track Log page and select ON. If you want to clear your old track log which you shut off at home select CLEAR>Yes or No option. Back on the Track Log page there is a setup page, I normally leave it alone, and use the defaults. Because you will get the chance to select the track color when you save your Track. When done select the Quit button. Walk you trapline, and on returning to your vehicle go back to the Track Log page, select OFF>SAVE>you will be asked if you want to save the entire track and select YES.
A new page will popup and you can name your track, it will provide you with track information and you can select a color for your track. And you can select the option to show it on your map.
When you return on day II you might want to start at the waypoint that you have created out of order. Use method described in Option 1. Once you are at that option and you want to follow the track, go to the Main Menu Page, select TRACKS>and use the rocker to scroll down to you saved Tracks>select the Track name for your present trapline>make sure the show on Map box is checked>scroll to the TracBack option and select it. Your map page will pop-up with your track on it. A pointer arrow will show on the map. Using the rocker to scroll to the point that you want to track back too. (There will be an arrow showing your current location on the map.) When you are on that point select Enter. You will be given two options (1) Follow Road or (2) Follow Track? Select follow track. The arrow (you) will show your location in relationship to the track. I normally use this visual method of back tracking or you can go to the compass page and follow the bearing pointer.
Hopefully this is not like scrambled eggs and you can make sense of it. Print a copy and take it with you.
My English teacher just rolled over in her grave.