If the picture that Andrew ( aka David) has of Dr. Mike looks familiar to Jane Seymour fans, it's because it was the same photo the her character Elise posed for in "Somewhere in Time"
Yosemite became a state park in 1864 and the 3rd national park in 1890.
The scene with the elk fighting has pine trees in the background. There are no pine trees in the background of any other scene throughout the series.
Dr. Quinn receives her third marriage proposal since moving to Colorado. The previous two were from the doctor in Boston and the local minister.
The male Elk battling for the Elk cows is foreshadowing of the physical confrontation between Sully and David/Andrew. This physical confrontation occurs in the next episode.