What were the three most task facing Mormon pioneers once they reached salt lake valley?

The three most urgent tasks facing Mormon pioneers once they reached the Salt Lake Valley were:

1. Securing food and shelter. The pioneers were exhausted from their journey and in need of food and rest. They immediately began planting crops and building homes.

2. Establishing irrigation systems. The climate in the Salt Lake Valley was much drier than the pioneers were accustomed to. In order to grow crops, they needed to build canals and ditches to divert water from nearby rivers and streams.

3. Preparing for defense. The pioneers were aware that they were vulnerable to attack from both Native Americans and other settlers. They quickly built a series of forts and established a militia to protect themselves.