This looks to be a chromolithographic trade card, but in fact is neither. It is an undivided back postcard on extra-heavy stock, mailed in 1907.
Printed by the firm of Gustav Monasch of Minneapolis, its reproduction is an interesting step, a variation of the developing four-color process
of halftone dots in cyan, magenta, yellow and black inks. This card uses CMYK inks, but only the black plate shows standard, regular halftone dots.
The other plates, especially the cyan (blue), use a somewhat irregular pattern.There is also a fifth color printed as a solid tan / flesh-colored tint.
The park, which opened in 1905 and closed in 1911, had a roller coaster, airship swing and a chute ride, a lighthouse tower, plus—for some reason—baby incubators!
This birdseye view was also issued as a poster.