There is a paved road which leaves I-15 at Littlefield AZ and heads north and east to Santa Clara UT. There is an area of Joshua trees which is located just across the Utah border and they often bloom in the spring. Most unusual and worth a trip if you are anywhere close. The first part of March seems to be the best time. Some were still blooming in April but seed pods were beginning to show on some and most had withered.