The Sasquatch's nest is where the 3 green stars (***) are in the picture in the link here: 1drv.ms/u/s!AvQhCl0SMET3x0riInhhAlJPwE_u?e=1tSgog.
To find the distance from Jeff to the nest (X in the picture above), we must first find the angles of the completed triangle in the picture below, via the following:
1) The angle in that completed triangle that is nearest to Carl and opposite from the distance X is 50° - 10° = 40°.
2) The angle between the line from Carl to Jeff and the line from Carl out to the East is 90° - 50° = 40°.
3) Now, since the angle between the directions South and East is 90°, then the angle between the line from Jeff to Carl and the line from Jeff down to the South is 180° - 90° - 40° = 50°.
4) Next, the angle between the line from Jeff to Carl and the line from Jeff to the Sasquatch's nest is 70° - 50° = 20°.
5) Finally, the angle opposite the line from Jeff to Carl is 180° - 40° - 20° = 120°.
Now, since you have all 3 angles of the completed triangle below, then you can find the distance X from the Law of Sines formula:
distance from Jeff to Carl distance from Jeff to nest
------------------------------------------------- = -------------------------------------------------
sine of opposite angle of that line sine of opposite angle of that line
So, we now have:
500 ft X
------------- = --------------- ---> X = 500 ft * sin(40°) / sin(120°) ≈ 371 ft
sin(120°) sin(40°) [rounded to the nearest foot]