Oil, natural gas and natural gas liquids revenues were $55.3 million and $47.0 million for the three months ended March 31, 2021 and 2020, respectively. For the three months ended March 31 2021 and 2020, production averaged 14,333 Boe/d and 18,791 Boe/d, respectively. Our average daily oil, natural gas and natural gas liquids production decreased in the first three months ended March 31, 2021 when compared to the same period in the prior year primarily due to production declines in our non-core areas, which were partially offset by increased production from our Monument Draw area, where new production came online as a result of our capital spending program. Also contributing to decreased total production in the current year period is a temporary shut-in of production in February 2021 as a result of inclement weather. The estimated production decrease associated with this temporary shut-in was approximately 1,300 Boe/d for the first three months of 2021. In addition, in December 2020, we divested properties that produced approximately 800 Boe/d during the three months ended March 31, 2020. Average realized prices (excluding the effects of hedging arrangements) were $42.84 per Boe and $27.50 per Boe for the three months ended March 31, 2021 and 2020, respectively. The amount we realize for our production depends predominantly upon commodity prices, which are affected by changes in market demand and supply, as impacted by overall economic activity, weather, transportation take-away capacity constraints, inventory storage levels, quality of production, basis differentials and other factors.
Lease operating expenses were $9.5 million and $12.5 million for the three months ended March 31, 2021 and 2020, respectively. The decrease in lease operating expenses in 2021 results from decreased salt water disposal costs due to lower production volumes and less produced water. On a per unit basis, lease operating expenses were $7.34 per Boe and $7.30 per Boe for the three months ended March 31, 2021 and 2020, respectively.
Workover and other expenses were $0.6 million and $1.3 million for the three months ended March 31, 2021 and 2020, respectively. On a per unit basis, workover and other expenses were $0.43 per Boe and $0.77 per Boe for the three months ended March 31, 2021 and 2020, respectively. The decreased workover and other expenses in 2021 relate to preventive operational measures previously undertaken to mitigate potential future failures in producing wells, continued improvements in well and completion designs, and cost reductions for materials and services.
Taxes other than income were $3.2 million and $2.9 million for the three months ended March 31, 2021 and 2020, respectively. Most production taxes are based on realized prices at the wellhead. As revenues or volumes from oil and natural gas sales increase or decrease, production taxes on these sales also increase or decrease. On a per unit basis, taxes other than income were $2.47 per Boe and $1.70 per Boe for the three months ended March 31, 2021 and 2020, respectively.
Gathering and other expenses were $13.2 million and $10.5 million for the three months ended March 31, 2021 and 2020, respectively. Gathering and other expenses include gathering fees paid to third parties on our oil and natural gas production and operating expenses of our gathering support infrastructure. Approximately $4.0 million and $2.9 million for the three months ended March 31, 2021 and 2020, respectively, relate to gathering and marketing fees paid to third parties on our oil and natural gas production. Gathering and marketing fees increased in 2021 as we marketed higher quantities of sour gas production to third parties in the current year period. Approximately $9.2 million and $7.6 million for the three months ended March 31, 2021 and 2020, respectively, relate to operating expenses on our treating equipment and gathering support facilities. The increase in treating equipment and gathering support facilities expenses in 2021 results from higher electricity and buy back fuel costs incurred as a result of inclement weather in February 2021 and higher chemical costs to improve the quality of treated oil, which were partially offset by lower operating expenses associated with our treating equipment, as fewer sour gas production volumes were processed through our hydrogen sulfide treating plant in the current year period.
Restructuring expense was approximately $0.4 million for the three months ended March 31, 2020. During the three months ended March 31, 2020, we incurred restructuring charges related to the consolidation into one corporate office and had reductions in our workforce due to efforts to improve efficiencies and go forward costs.
General and administrative expense was $4.2 million and $3.5 million for the three months ended March 31, 2021 and 2020, respectively. In late March 2020, due to changes in market conditions and decreased commodity prices, we determined that previously accrued discretionary cash incentives related to 2019 would not be paid, causing a $1.6 million reduction to general and administrative expense for the period. On a per unit basis, general and administrative expenses were $3.28 per Boe and $2.03 per Boe for the three months ended March 31, 2021 and 2020, respectively.