如何在R中绘制地图区域周围的矩形？

install.packages("ggplot2")
install.packages("maps")

library(ggplot2)
library(maps)

us_map <- map_data("state")

base_map <- ggplot() +
  geom_polygon(data = us_map, aes(x = long, y = lat, group = group), fill = "lightgray", color = "black")

xmin <- -125
xmax <- -115
ymin <- 32
ymax <- 42

rect_layer <- geom_rect(aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymax), fill = "transparent", color = "red", size = 1)

final_map <- base_map + rect_layer
print(final_map)